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REVIEW
Clinical Implementation of Comprehensive
Strategies to Characterize Cancer Genomes:
Opportunities and Challenges
Laura E. MacConaill1–3, Paul Van Hummelen1,2, Matthew Meyerson1–3,5, and William C. Hahn1,2,4,5
An increasing number of anticancer therapeutic agents target specific mutant
proteins that are expressed by many different tumor types. Recent evidence
suggests that the selection of patients whose tumors harbor specific genetic alterations identifies the subset of patients who are most likely to benefit from the use of such agents. As the number of genetic alterations that provide diagnostic and/or therapeutic information increases, the
comprehensive characterization of cancer genomes will be necessary to understand the spectrum
of distinct genomic alterations in cancer, to identify patients who are likely to respond to particular therapies, and to facilitate the selection of treatment modalities. Rapid developments in new
technologies for genomic analysis now provide the means to perform comprehensive analyses of
cancer genomes. In this article, we review the current state of cancer genome analysis and discuss
the challenges and opportunities necessary to implement these technologies in a clinical setting.
ABSTRACT
Significance: Rapid advances in sequencing technologies now make it possible to contemplate the
use of genome scale interrogation in clinical samples, which is likely to accelerate efforts to match
treatments to patients. However, major challenges in technology, clinical trial design, legal and social implications, healthcare information technology, and insurance and reimbursement remain.
Identifying and addressing these challenges will facilitate the implementation of personalized
cancer medicine. Cancer Discovery; 1(4): 297–311. ©2011 AACR.
THE CASE FOR INDIVIDUALIZED
CANCER MEDICINE
Work from many laboratories has identified genetic alterations that occur at an appreciable frequency in specific
types of cancers. For example, a reciprocal translocation between chromosome 9 and 22, known as the Philadelphia
chromosome and resulting in the BCR-ABL fusion gene,
occurs in ~95% of chronic myelogenous leukemias (CML;
refs. 1, 2); oncogenic KIT mutations are present in ~85%
of gastrointestinal stromal tumors (GISTs; refs. 3, 4); mutations in the serine-threonine kinase BRAF are present in
>50% of cutaneous melanoma (5); activating mutations in
Authors’ Affiliations: 1Center for Cancer Genome Discovery and 2Department
of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical
School; Departments of 3Pathology and 4Medicine, Brigham and Women’s
Hospital, Boston; 5Broad Institute of Harvard and MIT, Cambridge,
Massachusetts
Corresponding Author: William C. Hahn, Department of Medical Oncology,
Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215.
Phone: 617-632-2641; Fax: 617-632-4005; E-mail: william_hahn@dfci.
harvard.edu
doi: 10.1158/2159-8290.CD-11-0110
©2011 American Association for Cancer Research.
the epidermal growth factor receptor (EGFR) have been identified in ~15% of non–small cell lung cancers (NSCLC; refs.
6–8), and ERBB2 is amplified in 15–20% of breast cancers
(9–12). Biochemical studies confirmed that these genetic alterations result in constitutively active molecules, and tumors that harbor such mutations depend on the activity of
these proteins for survival.
On the basis of these observations, efforts to target these
molecules with either small-molecule inhibitors or antibodies have led to several agents that induce significant clinical
responses. For example, the tyrosine kinase inhibitor (TKI)
imatinib induces clinical responses in Philadelphia chromosome–positive CML (13) and GISTs that harbor KIT mutations
(14, 15); PLX4032 has been shown to induce responses in cutaneous melanomas with BRAF mutations (16, 17); the EGFR
TKIs erlotinib and gefitinib show activity in NSCLCs that
harbor activating mutations and small insertions/deletions
in EGFR (6–8); and the ERBB2 inhibitors trastuzumab and
lapatinib show clinical responses in breast cancers with amplification/overexpression of ERBB2 (18). Moreover, the presence
of mutations in proteins other than the intended therapeutic
target can affect the response to a particular therapeutic regimen. As an example, lung and colorectal cancers that harbor
mutations in EGFR as well as KRAS or BRAF fail to respond to
treatment with anti-EGFR–directed agents (19–22).
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MacConaill et al.
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SECTION
Genome technologies
Figure 1. Cycle of personalized
cancer medicine. Genomic
technologies will increasingly
be used in generating a profile
of cancer alterations for an
individual. This profile can be
used (for example) to stratify
patients for clinical trials, with
agents targeted to these specific
alterations, thus leading to more
effective treatment strategies.
The paradigm of personalized
cancer medicine cycles through
to improve diagnosis and
prognosis for each individual
patient.
“Individualized” profile
of cancer alterations
Diagnosis and prognosis
for individual patients
Target therapy trials
Cancer
genome
alterations
The field of molecularly based individualized cancer care
will thus be enabled and reinforced by a cyclical process (depicted in Fig. 1) of selecting treatment for an individual patient
based on the genetic expression, proteomic profiles, deregulated cellular pathways, and/or somatic mutations in cancer
cells of that particular patient; using this profile to accurately
define the prognosis in that patient; and suggesting treatment
options or clinical trials that are most likely to succeed (23,
24). However, further research and systematic screening of
the cancer genome are needed to uncover the full spectrum of
mutations that occur in both primary and recurrent tumors.
Moreover, because few of the targeted agents developed to date
induce durable remissions, it is likely that combination therapies based on rational combinations of targeted agents will be
necessary. In this review article, we focus on both the opportunities and the challenges presented by the implementation of
new genomic technologies that provide the potential to interrogate cancer genomes in the clinical setting and transform the
current cancer treatment paradigm.
currenT Molecular diagnosTic
sTraTegies
Although the number of molecular tests required for
clinical selection of patients for targeted therapy is increasing, the available technologies are limiting, and showing the
benefit of choosing patients for clinical trials on the basis of
the molecular subtype of their cancer is a lengthy process.
Currently, most cancers are categorized in terms of their
tissues of origin, the size of the primary lesion, and the presence of metastatic lesions. For solid tumors, the anatomic
origin of a tumor is generally the decisive factor in assessing
treatment options, and treatment choices are matched to
298 | CANCER DISCOVERY SEPTEMBER 2011 Targeted agents
Targeted agents
Cancer
genome
alterations
patients on the basis of factors such as primary tumor diagnosis or site, nodal status, histologic subtype, or hormone
receptor status. In hematologic malignancies, blood count
and microscopy are standard diagnostic tools used to categorize lymphomas and leukemias by cell lineage; a number
of these diseases can also be classified by cytogenetics [acute
myeloid leukemia (AML) and CML] or immunophenotyping of malignant cells (lymphoma, myeloma, and chronic
lymphocytic leukemia).
Currently, technologies to profile samples for the clinical
selection of patients for targeted therapies assess the mutational status of one or a few genes (capillary sequencing and
pyrosequencing) or interrogate a specific histologic or pathologic phenotype [immunohistochemistry and fluorescence
in-situ hybridization (FISH)]. Figure 2 highlights current and
emerging clinical technologies to detect various cancer DNA
alterations. For example, FISH is used to detect the translocation and resultant fusion of BCR and ABL in CML in clinical
settings (25, 26). The BCR-ABL translocation is also found
in acute lymphoblastic leukemia (ALL) at a lower frequency
(25–30%); thus molecular characterization of BCR-ABL is of
critical diagnostic importance in ALL, for which the presence
or absence of this alteration mutation will dictate therapy. In
a similar manner, amplification of ERBB2 in breast cancers
(27) and fusions involving the anaplastic lymphoma kinase
(ALK) gene (28) are detected by FISH and identify patients
who are likely to respond to anti-ERBB2 agents or smallmolecule inhibitors of ALK, respectively.
Several additional tests have been developed for other oncogenes. Detection of nucleotide substitution mutations,
insertions, or deletions within the kinase domain of EGFR
for gefitinib treatment is currently determined by capillary
gel sequencing. In the clinical setting, KIT mutations in
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Current clinical
technology
Molecular alterations in cancer
Point mutations (substitutions/indels)
Capillary
sequencing
Current
Current
clinical
clinical Emerging
Emerging
clinical
clinical
technology
technology
technology
technology
Pyrosequencing
Current clinical
EmergingREVIEW
clinical
Capillary
Capillary
sequencing
sequencing
Quantitative
PCR
technology
technology
Molecular
Molecular
alterations
alterations
in cancer
in cancer
Clinical Implementation of Cancer Genomes
Molecular
alterations
in cancer
PointPoint
mutations
mutations
(substitutions/indels)
(substitutions/indels)
PointMolecular
mutations
(substitutions/indels)
alterations
in cancer
Molecular
alterations
in cancer
Point mutations
(substitutions/indels)
Point mutations
(substitutions/indels)
Chromosomal aberrations (copy number gains or
Emerging clinical
technology
Current
clinical
Emerging
clinical
Pyrosequencing
Pyrosequencing
Current
clinical
Emerging
clinical
Capillary
sequencing
technology
technology
technology
technology
Quantitative
Quantitative
PCR PCR
Capillary
sequencing
Pyrosequencing
Capillary
sequencing
losses)
Pyrosequencing
Pyrosequencing
FISH, IHC
Quantitative PCR
Quantitative
PCR PCR
Quantitative
Massively parallel
sequencing
Chromosomal
Chromosomal
aberrations
aberrations
(copy(copy
number
number
gainsgains
or losses)
or losses)FISH, FISH,
IHC IHC
Chromosomal
aberrations
(copy (copy
number
gains or
losses)
Chromosomal
aberrations
number
gains
or losses)
FISH, IHC
FISH, IHC
Chromosomal aberrations (copy number gains or losses)
FISH, IHC
Translocations, fusion genes
Translocations,
fusionfusion
genesgenes
Translocations,
Translocations,
Translocations,
fusionfusion
genesgenes
Massively
Massively
parallel
parallel
sequencing
sequencing
Massively
parallel
Massively
parallel
Massively parallel
FISH, IHC sequencing
sequencing
sequencing
FISH, IHC
FISH, IHC
Translocations, fusion genes
FISH, FISH,
IHC IHC
FISH, IHC
Figure 2. Genome alterations, current tests, and future technologies: the major classes of genomic alterations that give rise to cancer, exemplary
cancer genes for each category, and the current and emerging clinical technologies for detecting these various types of alterations. TS, tumor
suppressor; IHC, immunohistochemistry.
GISTs can be detected using sequencing or quantitative PCR
(4, 29). Recently, sequencing assays have been developed to
detect mutations in BRAF (specifically, V600 alterations), and
agents targeting this alteration are now being evaluated in
clinical trials (30, 31). Table 1 lists the targeted therapeutic
agents (available or in clinical trials) for exemplary cancer
genes in each category of genomic alteration.
Beyond interrogating specific genes, several groups have
explored the use of gene expression profiling to discover signatures that identify specific subtypes of cancers or predict
the response to therapy. For example, Staudt and colleagues
(32, 33) showed that expression profiling can distinguish between germinal center B-like and activated B-cell–like lymphoma as well as identify poor prognosis in each group of
patients. Guidelines established by the American Society of
Clinical Oncology (ASCO) and the National Comprehensive
Cancer Network (NCCN) include the Oncotype DX assay,
which interrogates a 21-gene signature to predict benefit
from chemotherapy as well as risk of recurrence in breast cancer patients (34). MammaPrint is a microarray test (35, 36)
approved by the U.S. Food and Drug Administration (FDA)
to classify breast tumors for risk of recurrence. Further work
is necessary to determine whether these and other signatures
will become commonplace in clinical practice, as such tests
require substantially different protocols for the preparation
of samples than are ordinarily used by pathology laboratories; thus, the full predictive value of these tests requires additional evaluation.
The Technological revoluTion in
genoMics
The technological revolution in the field of genomics began over 30 years ago with the development of the Sanger
method for DNA sequencing (37), followed 20 years later by
the development of microarrays (38). Mass-spectrometric genotyping emerged as a useful technology shortly afterward
(39), and initial next-generation sequencing methodologies
were reported in 2005 (refs. 40, 41; see Fig. 3 for a timeline
of technological advances and concomitant cancer genome
landmark discoveries). Concurrent advances in the field of
sequencing resulted in the emergence of several massively
parallel sequencing technologies, which yield vastly greater
amounts of information. These sequencing technologies
have advanced DNA sequencing capacity at an unprecedented rate (refs. 40–43; for a comprehensive review on second-generation sequencing, see Shendure and Ji, ref. 44) and
lowered the cost per base of sequencing data by 10,000-fold
in the past decade (45).
The completion of a highly refined human genome sequence (46, 47) was a landmark achievement in establishing
a baseline reference genome to which other sequences could
be compared. The availability of such reference genomes has
enabled the concomitant characterization of genomic alterations from many different diseases, including cancers (48).
Technological advances in experimental and informatics
methodologies over the past 10 years have made possible the
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Table 1. Overview of cancer therapeutics available or in development for exemplary cancer genes in each category of
genomic alterations
Category of
genomic alteration
Exemplary cancer gene
Translocation/fusion
BCR-ABL
Amplification
Point mutation
Genotype
Cancer
CML
Targeted therapeutic agent
Imatinib, dasatinib, nilotinib
PML-RARα
Acute promyelocytic leukemia
All-trans retinoic acid (ATRA)
EML4-ALK
Breast, colorectal, lung
Crizotinib (phase III), foretinib (phase II)
FIP1L1-PDGFR
Chronic eosinophilic leukemia
Imatinib
EGFR
Lung, colorectal, glioblastoma,
pancreatic
Cetuximab, gefitinib, erlotinib,
panitumumab, lapatinib
ErbB2
Breast, ovarian
Trastuzumab, lapatinib
KIT
GISTs, glioma, HCC, RCC, CML
Imatinib, nilotinib, sunitinib, sorafenib
SRC
Sarcoma, CML, ALL
Dasatinib
PIK3CA
Breast, ovarian, colorectal,
endometrial...
PI3-kinase inhibitors, none
approved; experimental:
LY294002
EGFR
Lung, glioblastoma
Cetuximab, gefitinib, erlotinib,
panitumumab, lapatinib
KIT
GISTs, glioma, HCC, RCC, CML
Imatinib, nilotinib, sunitinib, sorafenib
PDGFR
GISTs, glioma, HCC, RCC, CML
Imatinib, nilotinib, sunitinib, sorafenib
BRAF
Melanoma, pediatric astrocytoma
PLX4032 (phase III)
MET
Lung
Cresatinib (phase III), foretinib (phase II)
KRAS
Colorectal, pancreatic, GI tract, lung…
Resistance to erlotinib, cetuximab
(colorectal)
RAS/RAF
CTCL
Selumetinib (phase II)
PTEN (mTOR)
Endometrial, prostate, NSCLC, renal
Ridaforolimus, temsirolimus, everolimus
PI3K/Akt (mTOR)
Endometrial, prostate, NSCLC, renal
Ridaforolimus, temsirolimus, everolimus
PTCH1, SMO (Hedgehog)
Basal cell carcinoma
GDC-0449 (vismodegib) (phase II)
VEGF-2578
Breast
Bevacizumab
VEGF-1154
Breast
Bevacizumab
Abbreviations: ALL, acute lymphoblastic leukemia; CML, chronic myelogenous leukemia; CTCL, cutaneous T-cell lymphomas; GIST, gastrointestinal stromal
tumor; HCC, hepatocellular carcinoma; NSCLC, non–small cell lung cancer; RCC, renal cell carcinoma.
characterization of cancer genomes. In initial studies, a genefocused approach used first-generation (Sanger) sequencing,
which resulted in the identification of many driver events
in cancers, such as mutations of BRAF in melanoma (5),
EGFR in NSCLC (6–8), JAK2 in myeloproliferative disorders (49, 50), FGFR2 in endometrial carcinoma (51), ALK in
neuroblastoma (52, 53), and PIK3CA in several cancers (54).
However, with the development of second-generation sequencing technologies, it is now feasible to sequence exomes
(known exons in the genome), transcriptomes (expressed
genes in the genome), or whole genomes of cancer samples.
Massively parallel DNA sequencing platforms have become
widely available, and the number of both normal and cancer
genomes that have been completed is now in the thousands
300 | CANCER DISCOVERY SEPTEMBER 2011 (42, 55–59). International efforts to sequence normal genomes [the 1000 Genomes Project (www.1000genomes.org)]
as well as cancer genomes [International Cancer Genome
Consortium (ICGC)] promise to provide a growing number
of reference whole-genome sequences. In the past 4 years, for
example, whole cancer genomes derived from AML (60, 61),
lung (62–64), breast (65–67), melanoma (68), and multiple
myeloma (69) have been reported in detail. Large-scale cancer
genome studies, such as The Cancer Genome Atlas (TCGA)
and the ICGC, are applying next-generation sequencing technologies to tumors from 50 different cancer types to generate
>25,000 genomes at the genomic, transcriptomic, and epigenomic level, and will provide the foundation for a complete
catalog of oncogenic mutations (70).
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Clinical Implementation of Cancer Genomes
1914
Theodore Boveri
proposes cancer
as a genomic
disease
REVIEW
1976
Transforming
sequence identified in
normal DNA src
1960
Nowell and
Hungerford identify
chromosomal
abnormality in CML
2002
Activating point
mutations identified
in BRAF
1982
Identification of mutated
proto-oncogene HRAS
Identification of Bcr-ABL
oncgenic fusion protein
on the Philadelphia
chromosome in CML
Identification of Myc as an
amplified oncogene
1970
Ludwig Gross
proposes a viral
origin of cancer
1970
1980
Technological advances
1972
First reported
recombinant DNA
technologies
1975
Sanger reports DNA
sequencing method
2008
Large-scale sequencing
efforts– TCGA, ICGC, others
First whole-genome cancer
sequences– AML, lung
cancer
2009
Whole-genome sequencing–
AML, breast cancer
2010
2005
Whole-genome sequencing–
Translocations identified lung, breast primary and
in solid tumors
metastasis, melanoma
1990
1982
Archetypes of cancer
alterations defined
2007
Large-scale sequencing– Sanger
2004
Activating point
mutations identified in
PIK3CA
Activating point
mutations and small
indels identified in EGFR
Cancer landmarks
1910
2006
Large-scale sequencing efforts–
genome-wide breast, colorectal cancers
2001
IHGSC report the
sequence of the
human genome
2000
1994
Microarrays for gene
expression and
sequence analysis
1986-7
CalTech reports first
semiautomated DNA
sequencing machine
1977
Maxam and Gilbert
report DNA sequencing
method
Bachetti and Graham
report method for DNA
transfer
1995
Mathies et al. reports
high-throughput dyebased DNA
sequencing
1998
RNAi screening to
specify gene
function
Massspectrometric
genotyping of
SNPs
2010
2020
2005
Next-generation sequencing:
massively parallel sequencing-by-synthesis
multiplex polony sequencing
four-color DNA sequencing-by-synthesis
2007
Integrative analytic approaches for
multiple types of large datasets
2008
Single-molecule DNA sequencing
2010
Single-molecule realtime DNA sequencing
Figure 3. Technological advances and concomitant developments in cancer biology: a timeline of the technological advances impacting cancer
research in the past 100 years. The landmark discoveries achieved with these technologies are indicated above the line. The number of these
landmarks has increased dramatically in the past 10 years, owing in large part to next-generation sequencing capabilities. IHGSG, International
Human Genome Sequencing Consortium; RNAi, RNA interference; SNP, single-nucleotide polymorphism.
Translating Individualized Medicine
to the Clinic
The result of this explosion in the molecular characterization of cancer is an emerging vision for personalized cancer
medicine. In this paradigm, the specific genomic alterations
driving a patient’s tumor will be analyzed, and a targeted
therapy or therapies will be recommended in accordance with
the genomic characterization of each tumor. This process will
maximize efficacy of treatment while minimizing undesirable
side effects. Significant challenges currently exist that will
need to be overcome to realize the goal of tailored treatments
based on tumor genomics. The challenges and opportunities
facing scientists, researchers, clinicians, and oncologists in
the near future are the subject of this review. Three pivotal
components will be required to enable a paradigm shift to
personalized cancer medicine:
• Every patient is profiled to identify genetic alterations
present in a specific cancer.
• Caregivers have access to this information in a form that
provides relevant contextual information.
• This information can be obtained within a time frame
that permits its incorporation into the decision-making
process.
An increased understanding of the biological driver
events for some cancers, coupled with advances in technologies used to detect somatic cancer alterations, has led
to the establishment of some initial personalized cancer
medicine programs at several cancer centers, including the
Dana-Farber/Brigham and Women’s Cancer Center (71, 72),
Massachusetts General Hospital (73, 74), Memorial SloanKettering Cancer Center (75–77), MD Anderson Cancer
Center (78), Oregon Health & Science University (79), and
Vanderbilt Cancer Center (73). Each of these programs uses
a genotyping platform to profile patient samples for alterations in a panel of potentially “actionable” or “druggable”
gene mutations that may inform a therapeutic paradigm
for patients. Currently, these initiatives are limited by the
number of genes interrogated, the type of somatic alteration investigated (mostly mutations and small insertions/
deletions), throughput and cost of technology, and types of
cancers being screened. Additional efforts are under way to
translate the recent advances in genome technologies (such
as massively parallel, whole-genome sequencing) into the
clinical setting to guide patient treatment options.
Although advances in technology and the biological understanding of cancer pathogenesis have brought the goal
of personalized cancer medicine closer, important challenges
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remain, pertaining to each step described above, before this
vision of individualized cancer care is actualized. These challenges are discussed in detail below.
CHALLENGES IN IMPLEMENTATION OF
PERSONALIZED CANCER MEDICINE
Technological Challenges in Sample Preparation
Diagnostic interventions that successfully introduce
tumor mutation profiling to clinical practice must circumvent several technical and logistical difficulties. Important
limitations in the deployment of genomic technologies in the
clinic are the minute amounts of tumor material available
for genomic profiling and the availability of tissue in forms
amenable to available technologies.
A barrier to large-scale genomic interrogation is the specimen itself. Many of the research-oriented, large-scale cancer-sequencing efforts thus far focus on surgically resected
samples that yield a large amount of tissue for analysis. In the
absence of a surgical resection, however, biopsy specimens
taken for diagnostic purposes are often small and are usually
composed of both normal and malignant cells in a variable
ratio. Moreover, for some common cancers, such as those of
breast and prostate, primary tumors are often identified at
an early stage when they are small. Incorporation of genomic
profiling into clinical decision making will therefore require
reliable genomic profiling of small specimens, diffuse biopsy
samples, and fine-needle aspirates.
In addition to the availability of limiting quantities of material for genomic profiling, the quality of nucleic acids can
also vary greatly from sample to sample. The standard practice of banking formalin-fixed, paraffin-embedded (FFPE)
clinical specimens (whether from surgical resections or biopsies) is advantageous for a clinical laboratory that performs
histologic diagnoses. The majority of specimens are fixed for
purposes other than genetic characterization, and this process often results in degraded and/or chemically modified
nucleic acids (80–82) that are unlikely to yield the quality
or quantity of DNA necessary for many high-throughput
genomic technologies (83). Thus, any clinical test must be
able to accept as input nucleic acid material derived from
FFPE and/or archival tumor specimens.
In addition, samples derived from tumors are rarely homogeneous. For example, many tumors contain large areas
of necrotic tissue that reduce the overall amount of usable
DNA. Furthermore, specimens contain a mixture of normal
cells and cancer cells, and the identification method must
therefore have sufficient sensitivity to detect mutations in
samples in which the tumor often represents less than half of
the material. Many cancers are also populations of heterogeneous cells (84), with events that occur throughout the time
line of tumor evolution (85). Finally, the emergence of resistance mutations is a clinically relevant genotype that may
have impact on a therapeutic regimen and is, in some cases,
driven by a mutation that may be present initially (whether in
the target of therapy or an entirely different gene) in a small
subclone of cancer cells (86–89). As these mutations may be
present in only a fraction of tumor cells examined (90), even
greater sensitivity is required to detect low-level events (91).
302 | CANCER DISCOVERY SEPTEMBER 2011 The Selection of Genomic Approach and Platform
Until recently, a major limiting factor inherent in the
detection of cancer genomic alterations has been the availability of technologies to assay samples for all types of alterations; however, recent major technological innovations
have all but eliminated this as a bottleneck in the translation of individualized cancer profiling to the clinical setting.
Capillary sequencing, used to detect point mutations, insertions, deletions, and substitutions at the DNA level, is still
considered the gold standard in clinical laboratories and is
used to detect EGFR mutations in lung cancer and KRAS
mutations in colorectal cancer, among others. More sensitive sequencing technologies, such as pyrosequencing, are
also routinely used in the clinical laboratory for detection
of small base-pair changes in genes. Comparative genomic
hybridization (92), FISH, and array comparative genomic hybridization (93) allow the detection of genomic imbalances,
including copy-number alterations and deletions at a low
resolution. Mass-spectrometric analysis of DNA enables the
detection of base-pair changes, as well as small (<50 bp) insertions and deletions in genes (71, 72, 94, 95).
However, the implementation of these technologies in a
clinical setting will be challenging for several reasons. Some
limitations can be attributed to the inherent technical aspects of PCR and DNA manipulations in general. Moreover,
the data output from hybridization-based tests is subject to
error, and both comparators (such as wild-type or normal)
and replicates are necessary to inform a conclusive test result. In the case of mass-spectrometric tests and sequencing, the signal generated is plotted as a composite intensity
peak and (similar to hybridization-based methodologies)
is subject to saturation limits and necessitates a subjective
interpretation.
Second-generation sequencing technologies (such as
Illumina and SOLiD) are better candidates to incorporate
into the clinical setting. They permit the detection of the
full range of genomic alterations, including mutations,
structural rearrangements, and copy-number changes, using a single approach (refs. 60–64, 66, 68, 96; for a comprehensive review of genomic sequencing strategies and
technologies, see ref. 96 and references therein) to detect
epigenetic modifications with chromatin immunoprecipitation (ChipSeq; ref. 97) and alterations in RNA (98), such as
transcript expression, allele-specific expression, and alternative splicing. The theoretical sensitivity of second-generation technology platforms can be increased by sequencing
to a higher coverage. In addition, protocols for analyzing
samples derived from FFPE are available (83).
Current difficulties with these sequencing platforms
include the lack of validation efforts, high running costs,
and slow turnaround time. The reliability and reproducibility of second-generation sequencing platforms have yet
to be established. International comparative studies may
therefore need to be organized, similar to the MicroArray
Quality Control project (MAQC) for the assessment of quality and reproducibility between microarray platforms and
microarray data–generating laboratories (99). The MAQC
effort was instrumental in the scientific community’s acceptance of and confidence in microarray data.
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Clinical Implementation of Cancer Genomes
Costs and throughput in sequencing the full genome will
need to decrease by an order of magnitude before these technologies can be used routinely in clinical laboratories. Many
research and diagnostic goals, however, may be achieved
much sooner by sequencing a specific subset of the genome
in large numbers of individuals or at a greater sequencing depth. Several advances, including barcoding DNA for
multiplex sequencing (100, 101) and hybridization-based
sequence capture methods, reduce the complexity of the
total genome (102–105) and decrease the cost, increase the
number of applications of next-generation sequencing, and
retain sensitivity sufficient to detect low abundant somatic
mutations (106). Transcriptome sequencing is a sensitive
application for detecting intragenic fusions (including inframe fusion events that lead to oncogene activation; refs.
107, 108) and for generating gene expression profiles (109).
Second-generation sequencing technologies currently have
a slow turnaround time (1–2 weeks) and are still quite costly.
To accommodate a clinical setting, technological advances
are required to achieve the performance necessary for clinical
implementation, including short turnaround time (on the
order of days), high accuracy and sensitivity, inter- and intralaboratory reproducibility, and cost-effectiveness. Additional
modifications in chemistries and detection methodologies,
as well as a decrease in the experimental surface areas, may
enable such advances. Recently, smaller, faster versions of
available technologies have been released. These “personal sequencers” (produced by Intelligent Biosystems and Illumina,
among others) have outputs sufficient for analysis of 1 exome
that can be generated within a day. Going forward, faster
(third-generation) sequencing technologies may have the
ability to interrogate cancer genome alterations on a singlemolecule or per-cell basis, and possibly enable noninvasive
methods for cancer diagnosis and monitoring.
Analytical and Informatics Issues in Cancer
Genome Diagnostics
A challenge deriving from the interrogation of low-quality
tumor samples subject to the biological confounders detailed
above is the analysis of data from cancer genome characterization efforts. Because of issues such as tumor heterogeneity, ploidy, and stromal contamination, a heterozygous
somatic mutation in a tumor specimen with 60% admixed
normal cells will be detected at an overall allele frequency of
20%. Thus mutation-calling algorithms can be confounded
by the presence of additional (normal) signal, and disambiguating a somatic mutation signal from background can be
difficult. Similar issues apply to the detection of other types
of alterations, such as copy-number changes and chromosomal rearrangements. With regard to current technologies,
massively parallel sequencing can overcome or mitigate some
of these problems. The data output from these technologies
is essentially digital—that is, one can count the number of
reads, alleles, or nucleotides at any position on the aligned
sequence. The advantage of this digital readout of data is that
counting the number of reads that identify mutant alleles
can help to overcome obstacles of low tumor quantity, variable ploidy, tumor heterogeneity, and normal cell admixture.
Challenges in the detection of somatic alterations in tumor
specimens can thus be addressed using statistically rigorous
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algorithms and bioinformatics approaches (for a comprehensive review of considerations in the analysis of cancer
genomes, see ref. 96). Complete cancer genome sequencing
requires that both the tumor and the matched normal sample be significantly oversampled. Specifically, the nucleotide
sequence of the same fragment of DNA is sequenced repeatedly to gain a confident, high-quality readout sequence (42),
which allows identification of somatic variants (as opposed
to germline alterations, which may be private or common)
that can be selected as candidates for further interrogation.
From a diagnostic perspective, it may be prudent to have a
high-quality cutoff for clinically relevant somatic mutations,
or candidate events can be validated using an orthogonal
technology, such as genotyping, pyrosequencing, or capillary
sequencing, preferably in Clinical Laboratory Improvement
Amendments (CLIA)–certified laboratories.
The vast amount of information produced from wholegenome sequencing studies presents a challenge of its own.
Indeed, new algorithms are at present being developed to
translate raw sequence data into meaningful reads that can
be used to analyze the variety of genomic endpoints. A number of groups and approaches are currently in development,
including mrFAST for copy-number variation by Alkan
et al. (110); the genome analysis toolkit (GATK) developed by
DePristo and coworkers for single-nucleotide polymorphism
(111) and genotyping discovery; and several ChipSeq analysis
tools reviewed by Kim et al. (112).
Besides new algorithm development, the computational
cost for storage and processing of data is another challenge
and may approach that of sequencing itself. These factors
suggest that it may be more parsimonious to keep a record of
only the deviations of a patient’s tumor (and normal) from
a reference genome. Another important consideration for
clinical sequencing is a robust sample tracking, management,
and laboratory information management system, as maintaining the identity of a sample is critical. The abundance of
sequence information that will be collected using a sequencing technology in the clinical setting is advantageous: it permits identification of somatic tumor alterations, as well as
matching of the tumor with the corresponding normal (or
germline) events that will be seen in both matched samples,
thus ensuring that sample identity can be maintained.
Interpretation of Biological Data
Whole-genome studies have shown that the number and
type of alterations in cancer genomes are often diverse and
complex. Signals of driver alterations (those that dysregulate growth or promote tumorigenesis) are often difficult to
distinguish from passenger events (alterations that are inconsequential and do not contribute to tumorigenesis). The
significance of a somatic event must therefore be assessed in
the context of the background of additional somatic events
that may not have physiological consequence. Integrating
datasets and genomic endpoints may help in identifying
driver mutations or pathways. The initial findings of TCGA,
for example, demonstrated the utility of this approach by
using integrative analyses of DNA sequence, copy number,
gene expression, and DNA methylation in glioblastomas to
provide a network view of altered pathways (113). However,
this approach requires sufficient biological knowledge of
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the relevant pathways, relationships, and interactions to be
able to interpret and understand signals. Nevertheless, for
diagnostic purposes, distinguishing driver from passenger mutations may not be that relevant, but for prognosis,
it is important to understand the master regulating genes
or pathways to predict disease progression and response to
targeted personalized therapy. Determining driver events
or molecular targets is an emerging area recognized by the
National Cancer Institute in efforts such as the Cancer Target
Discovery and Development Network to prospectively pursue this path and to test strategies for selecting therapeutic
targets (114).
A related question concerning the use of genomics to guide
therapeutic decisions for cancer is whether mutations predictive of pharmacologic sensitivity in one tumor type can be
extended to predict sensitivity in other tumor types. Many
oncogenic KIT mutations that are predictive of imatinib
response in GISTs have been identified. The subsequent discovery of identical KIT mutations in some acral and mucosal melanomas (115) allowed assessment of this hypothesis.
Several reports indicate that inhibition of KIT using imatinib
or nilotinib can elicit clinical responses in KIT-mutant melanoma (116, 117). These observations suggest that known
driver genomic events may have the potential to denote therapeutic vulnerability regardless of the tissue type in which they
occur, although clinical studies will be necessary to confirm
this idea in many cases. Other reports, however, have contradictory findings and indicate that cellular context does play
a role: for example, ovarian cancer patients with PIK3CA and
either KRAS or BRAF mutations respond to treatment with a
phosphoinositide 3-kinase (PI3K) pathway inhibitor, whereas
colorectal cancer patients with PIK3CA and KRAS mutations
do not respond (118).
A critical step toward defining correct personalized anticancer therapy is the identification of the additional genes
and pathways altered in the tumor, and the elucidation of
their particular oncogenic role. Genetic interactions and
compensatory mechanisms may therefore be challenging for
determining cancer treatment (see ref. 119 for a review), and
the treatment paradigm for a patient thus may not be decided on the mutational status of a single gene, but instead
on the context in which that mutation is found. As detailed
above, mutations in genes other than the predicted therapeutic target can dramatically affect the response of a patient to a
specific therapy, as in the case of RAS and RAF mutations indicating no response to EFGR inhibitor therapy in colorectal
cancer and NSCLC (19–22). Treating metastatic melanoma
patients with a BRAF-selective inhibitor, in the presence of
RAS mutations, may unintentionally activate the mitogenactivated protein/extracellular signal regulated kinase (ERK)
kinase (MEK)/ERK signaling pathway, instead of inhibiting
tumor formation (120). The presence of additional mutations
in intracellular signaling pathways activated by receptor tyrosine kinases can exhibit patterns of cross-talk. To this point,
it has been reported that inhibition of certain pathways, such
as the mTOR route, may lead to increased mitogen-activated
protein kinase (MAPK) activity (121). Therefore, ablation of
signals through both routes may be required for efficient antitumor activity. Moreover, combined inhibition of PI3K and
MAPK routes has shown superior antitumor effect compared
304 | CANCER DISCOVERY SEPTEMBER 2011 with individual targeting of either pathway (122). Another
example is the sensitivity of BRCA1/2-deficient tumor cells
to PARP inhibitors. PARP has been shown to be critical to cell
survival in a compensatory mechanism for BRCA1 or BRCA2
loss-of-function mutations (123).
Accurate representation of the significance of a variant
is critical—translating this information to physicians, clinicians, and oncologists requires a thoughtful analysis of the
utility of available data. As the current approach to clinical characteristics that drive analyses today transitions to a
more nuanced and realistic representation of the complexity
of individual human physiology, robust decision support systems will be vital as an adjunct to the clinician’s evaluation.
A system based on levels of evidence, for example, might indicate to a provider how much information has been collated
for a specific mutation, tissue type, and therapeutic target.
This information would aid in treatment decisions; as more
exome-based and genome-based sequencing approaches
translate to the clinical arena, a database linking to approved
indications and guidelines may assist in collating the mass of
information into a more interpretable framework. Regardless
of the sophistication of informatics support, thoughtfully
designed and carefully monitored clinical trials will be necessary to safely and effectively disambiguate the complex network of molecular alterations, signaling pathways, cellular
context, and response to a particular therapeutic regimen.
Disease Monitoring
The molecular signature of a tumor during progression
can be dynamic, one consequence of which is the emergence
of resistance during therapy. Clinical responses to targeted
anticancer therapeutics are frequently confounded by de novo
or acquired resistance (15, 124, 125). Logistically, then, it
would be ideal to sample a tumor at diagnosis and then
track the progression of disease by recurrent sampling. This
practice would aid in the management of disease and might
indicate the emergence of resistance mutations. The clinical
promise of selective RAF inhibitors, for example, has widespread ramifications for patient treatment, yet single-agent
targeted therapy is almost invariably followed by relapse
caused by acquired drug resistance. Identification of resistance mechanisms in a manner that elucidates alternative
druggable targets may inform effective long-term treatment
strategies (126).
Recent studies have shown that mutant BRAF-specific
inhibitors can activate CRAF through the formation of dimeric RAF complexes, and this process is enhanced by the
presence of an oncogenic RAS mutation. Thus these inhibitors should be used for treating cancers driven by BRAF, but
should be avoided in cancers caused by RAS mutations (127,
128). Similarly, resistance to RAF inhibition can be achieved
by multiple MAP3K-dependent mechanisms of MEK/ERK
reactivation (129) but might be intercepted through combined therapeutic modalities for MAPK pathway inhibition.
Thus, identification of the correct combination of therapeutic agents targeting several key steps in signaling pathways
will be a new paradigm for cancer management.
However, whether acquired resistance is due to compensatory mechanisms/mutations or due to the selection of existing mutations within a heterogenic tumor is not yet clear.
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Clinical Implementation of Cancer Genomes
Several recent studies suggest that cancer genomes evolve as
the cancer progresses. Deep sequencing of two primary breast
cancers and subsequent metastases showed either novel
mutations or enrichment for low-frequency mutations in the
metastases, indicating that analysis of such tissues in some
cancers might identify additional mutations that may be important drug targets (65, 66).
In many cases, it may be convenient to diagnose or detect
the molecular signature of a tumor using noninvasive procedures. To this end, much effort is focused on the development of technologies to detect genomic alterations in
circulating tumor cells (CTCs; refs. 130–132) or plasma DNA
(133–135). The efficacy of using tumor-derived CTCs in the
monitoring of disease and the early detection of resistance
mutations during treatment have been reported for EGFR
in lung cancer (130) as well as other solid tumor metastases
(132); prospective clinical trials are under way in metastatic
breast cancer. An FDA-approved technology for detection has
also shown promise in characterizing the molecular profile
(specifically HER2 expression) of CTCs in breast cancer patients (136). Next-generation sequencing could be the ideal
technology to screen CTCs now that enough DNA can be
extracted from flow-sorted single nuclei (137).
Clinical Trial Design
As our knowledge of the myriad alterations that drive cancer biology increases, our ability to accurately interpret these
somatic alterations (and transfer patients to the appropriate
targeted therapy) will become more refined. Thus, personalized diagnostic technologies may aid in the stratification
and enrollment of patients with specific molecular alterations for a clinical trial with a targeted therapeutic regimen.
One might therefore design clinical trials based on a targeted
genotype, rather than the cancer type, and to select patients
based on that genotype. It is clear that selecting patients with
different cancers by mutation will be challenging owing to
the heterogeneity of the natural history of the cancers, as well
as the question of whether different responses will be found
in tumors derived from different tissues even if they harbor
the same genetic alteration.
To date, success with molecularly characterized targeted
therapeutic trials has occurred with cancer types in which the
hallmark mutation is present in a large subset of specimens
as defined by tissue type or histologic classification. For example, KIT mutations occur in ~85% of GISTs (14, 138), and
targeted therapies such as imatinib mesylate are effective only
in patients with alterations in the intended targets (mutated
KIT or PDGFRα; refs. 139, 140). Evidence is increasing, however, that these potentially actionable events occur at lower
frequencies in other cancer types, and thus patients harboring
these alterations are potentially suitable candidates for a targeted therapy; this concept is the basis for the paradigm of personalized or individualized cancer medicine. NSCLC patients,
for instance, can harbor activating mutations in EGFR, but
also KRAS, BRAF, PIK3CA, ERBB2, or translocations involving
ALK (28, 141, 142). Similarly, SLC45A3-BRAF and ESRP1-RAF1
fusions were observed in frequencies below 2% in patients with
advanced prostate cancer, gastric cancer, and melanoma, and
may therefore be sensitive to RAF or MEK inhibitors (143).
Improvements in our understanding of chemical biology
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and drug targets should also aid in the interpretation of clinical trial data and enhance our understanding and interpretation of the biological response to specific treatment paradigms.
The first BRAF-targeting drug to enter the clinic, for example,
was sorafenib, a type II multikinase inhibitor (144–146). In
clinical trials, sorafenib was ineffective in BRAF-mutated melanoma (147), but effective in renal cell (148) and hepatocellular
carcinoma (149). Thus the interpretation of clinical trial data
can be confounded by the relative specificity and potency of
inhibitors in specific cancer types as well as off-target effects.
The efficacy of a specific BRAF V600E inhibitor in clinical trials
demonstrates the power of using targeted, mechanistic inhibitors (30, 150); the necessity of adding combination therapies
to offset the cellular resistance to such drugs (151) indicates
that our ability to interpret these data is still limited. Carefully
designed and controlled clinical trials, in combination with robust genomic profiling technologies, will be needed to define
the effective mutation-drug combinations.
It is imperative that new tests, drugs, and procedures in
patients be subjected to rigorous appraisal, and that new signatures of relapse risk, such as that described for colon cancer, should also be tested in prospective clinical trials (152).
The efficacy of such clinical trials has been shown in stratification of NSCLC patients based on the mutational status
of EGFR (153, 154). Additional large-scale, prospective randomized clinical trials are under way for breast cancer gene
expression tests.
With the cost of genome sequencing decreasing dramatically,
it may be feasible in the not-too-distant future to augment
clinical trials of cancer drugs with complete cancer genome or
transcriptome sequencing in order to identify these determinants. It has yet to be determined, however, if clinical trials will
be required to show the value of comprehensive cancer genome
profiling, and what form those trials should take. We refer the
reader to recent reviews that discuss new approaches to clinical
trial design and development of new therapeutics (155–158)
Ethical, Legal, and Social Implications and
Intellectual Property Challenges
Patients and subjects must give consent properly, as well as
be educated with regard to the import and impact of genomic
testing. Privacy issues may also be a concern for the patient.
The United States FDA recently updated its requirements for
informed consent documents used in clinical trials of drugs,
biologics, and medical devices, to include a statement informing participants that information from trials will be entered
into a databank. For somatic mutations and current clinical
tests assaying a small number of DNA changes, this information can be linked to the patient’s medical record when
contained within in a secure database with restricted access.
Looking ahead to sequencing-based approaches, we suspect
that the need to protect this patient’s data and confidentiality will arise. In the United States, the Genetic Information
Nondiscrimination Act was passed in 2008 to protect against
discrimination (health insurance and employment) based on
genetic information, and was seen as a landmark achievement in enabling patients to take advantage of personalized
medicine without fear of discrimination.
As more genome-wide association studies are completed
across populations, individual germline differences between
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patients will also be factored into the equation—lower penetrance alleles in many coding and noncoding regions can
help inform the progression of disease, response to therapy,
and metabolism of specific compounds. Testing for diseasecausing mutations in the BRCA1 and BRCA2 genes (implicated in familial breast and ovarian cancer syndromes) is
an early example of the contribution of germline features
to disease prognosis. Discovery of a disease-causing mutation in a family can inform at-risk persons about whether
they are at higher risk for cancer and may prompt individualized prophylactic therapy. Another consequence of using
sequencing-based technologies is the generation of ancillary
or unintentional data. This imight come in the form of sequence alterations that were not being screened or tested for
but that may impact the health or treatment of the patient
(and possibly related individuals) in other ways.
Public education on the potential benefits of personalized cancer medicine and individualized treatments
will be an important facet of its widespread acceptance.
Furthermore, the implementation of these technologies will
require several levels of additional oversight, such as obtaining Institutional Review Board–approved consent for
appropriate testing, with a view to ensuring ethical research
conduct and adequate subject protection (for a review on
electronic health records and healthcare information technology considerations in personalized medicine, see ref.
159). Considerations such as privacy concerns and the unknown clinical significance of genome sequence data must
be weighed against the ethical principles of respect for autonomy and the right of every patient to receive relevant personal medical information. As next-generation sequencing
technologies and genomic science filter into clinical medicine and standard of care, guidance from programs such as
the Department of Energy- and NIH-funded Ethical, Legal
and Social Implications Research Program will be needed in
order to adequately protect subjects and patients.
A number of additional hurdles currently confound the
process of implementing personalized cancer profiling in the
clinical setting, including a pre-existing intellectual property (IP) environment that gives a company the sole right to
genetic tests of specific genes and mutations. The arena of
gene-based IP is currently in flux with regard to clinical diagnostics and patented genes. Addressing these changes in the
architecture of cancer care may require a substantial shift in
the cultural understanding of individualized cancer medicine
and how it affects each party in the arena of cancer care.
Oversight and Regulatory Challenges
In the United States, several large stakeholders currently use the output from clinical research to make decisions and set policy. Three of the largest are the U.S. FDA,
the Agency for Healthcare Research and Quality, and the
Centers for Medicare & Medicaid Services (CMS). Whereas
the FDA regulates diagnostic devices sold as kits (Medical
Device Amendments of 1976), the CMS regulates diagnostic
tests that are developed and performed in clinical laboratories under CLIA certification. Generally, FDA clearance
of in vitro diagnostic devices includes evaluation of the performance claims of the assay, whereas CLIA laboratory inspections focus on reference laboratory quality standards.
306 | CANCER DISCOVERY SEPTEMBER 2011 In addition, many state health departments require their
own certifications for tests performed on patients from
their state, and these inspections review assay validation
reports for in-house–developed tests in detail. The Clinical
and Laboratory Standards Institute publishes standards
on assay validation and performance (160). Furthermore,
large reference laboratories generally have adopted assay
validation and acceptance policies to comply with pharmaceutical industry guidelines and expectations, including
International Conference on Harmonisation of Technical
Requirements for Registration of Pharmaceuticals
for Human Use, Good Clinical Practice and Good
Laboratory Practice, and International Organization for
Standardization accreditation.
The proliferation of a consensus interpretative framework providing recommendations to clinicians and oncologists would be helpful for personalized cancer medicine.
One possible structure would be a form similar to that of
the NCCN or ASCO, in which a centralized body (or bodies) collates information on clinical trials and issues guidelines on clinical policy in oncology based on a system akin
to “levels of evidence.” Guidelines on personalized cancer
medicine could be issued in the form of an annual guide, for
example, and made available in an affirmed database. These
guidelines would be based on the strength of evidence available from preclinical and clinical trials. The result of this
interface between cancer centers would be a gradual shift
from empirical cancer treatment options to more individualized (and effective) therapies.
An unintentional but nonetheless important consequence
of creating a cross-disciplinary, integrated framework is the
empowerment of any participating cancer center with clinical
trials of sufficient volume. A linked database could then act
as a venue to interpret the findings of clinical trials and to
determine the therapeutic significance of an individual mutation or a spectrum of alterations. This framework could
encourage the emergence of professional and patient-centric
networks and support groups, and function as an interface
between individual cancer centers and a more global network
of participants.
Overall, realizing the goal of personalized cancer medicine
will require the systematic engagement of all interested parties: patients, oncologists, cancer centers, large cooperative
clinical trials groups (such as the National Surgical Adjuvant
Breast and Bowel Project), pharmaceutical companies, insurance providers, and government and regulatory agencies.
Some tentative movement has been made in this direction,
with the emergence of the drug-diagnostic codevelopment
paradigm (161), whereby drug development groups team
with diagnostic entities to develop a companion test for their
therapeutic. The proliferation of targeted agents in development and clinical practice necessitates concomitant implementation of companion diagnostic approaches that enrich
for subpopulations most likely to respond to a drug.
Concluding Remarks
Ongoing global genome characterization efforts are revolutionizing both tumor biology and the optimal paradigm
for cancer treatment to an unprecedented degree. The pace of
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Clinical Implementation of Cancer Genomes
KEY CONCEPTS AND RELEVANCE
• Genomic Strategies in Cancer Medicine
Cancer is a genomic disease; newly developed
targeted therapies in cancer medicine are based
on the mutational status of one or a set of particular genes in the tumor sample.
• Personalized Cancer Medicine
With the advent of new technological breakthroughs, analyzing a complete cancer genome in
great detail at a reasonable cost is now feasible
and can be used for personalized treatment and
disease-monitoring approaches.
• Disruptive Genomic Technologies
The current and emerging technologies enable
comprehensive genome-wide analysis of the
alterations that are a hallmark of cancer.
• Clinical Implementation Challenges
Despite the inherent complexity of cancer genomics, incorporating the knowledge of the molecular
basis of cancer into clinical decision making will
speed the advent of more effective anticancer
therapies. The challenges (in many different fields)
relate to the implementation of comprehensive
screening of a patient’s cancer genome for diagnostic and/or therapeutic use. These challenges lie
in the areas of technologies, clinical trial design,
legal and social implications, healthcare information technology, and insurance and reimbursement.
advance is empowered in large part through technological innovations that render complete cancer genome characterization feasible on a large scale. The technologies available in the
research setting today will become the clinical tests of tomorrow. In the near future, traditional diagnostic and prognostic
factors will be supplemented by tumor genomic signatures,
well-characterized molecular therapeutic targets, chemotherapy response assays, and the identification of deranged
molecular pathways. Despite the inherent complexity of cancer genomics, incorporating this knowledge of the molecular basis of cancer into clinical decision making will speed
the advent of more effective anticancer therapies. Realizing
the goal of individualized cancer medicine necessitates the
concomitant engagement of academic thought leaders, clinicians, oncologists, cancer centers, government and regulatory
agencies, and patient advocacy groups. Molecularly based individualized cancer care will have a tremendous impact on
the future of oncology. Personalized cancer genomics, once
widely available and translated into the clinical setting in an
appropriate and thoughtful manner, will greatly improve the
lives of many cancer patients.
Disclosure of Potential Conflicts of Interest
No potential conflicts of interest were disclosed by L.E. MacConaill
and P. Van Hummelen. M. Meyerson is a consultant for and received
research support from Novartis; the founding advisor of, consultant
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for, and equity holder in Foundation Medicine; a coinventor and patent holder on the use of EGFR mutations for lung cancer diagnosis,
licensed to Genzyme Genetics/Labcorp. W.C. Hahn is a consultant
for Novartis and Thermo-Fisher and has received research support
from Novartis.
Acknowledgments
We thank our many colleagues whose work could not be cited
owing to space limitations.
Received May 12, 2011; accepted August 4, 2011; published online
September 15, 2011.
REFERENCES
1. de Klein A, van Kessel AG, Grosveld G, Bartram CR, Hagemeijer
A, Bootsma D, et al. A cellular oncogene is translocated to the
Philadelphia chromosome in chronic myelocytic leukaemia. Nature
1982;300:765–7.
2. Rowley JD. A new consistent chromosomal abnormality in chronic
myelogenous leukaemia identified by quinacrine fluorescence and
Giemsa staining [letter]. Nature 1973;243:290–3.
3. Hirota S, Isozaki K, Moriyama Y, Hashimoto K, Nishida T, Ishiguro
S, et al. Gain-of-function mutations of c-kit in human gastrointestinal stromal tumors. Science 1998;279:577–80.
4. Heinrich MC, Corless CL, Demetri GD, Blanke CD, von Mehren
M, Joensuu H, et al. Kinase mutations and imatinib response in
patients with metastatic gastrointestinal stromal tumor. J Clin
Oncol 2003;21:4342–9.
5. Davies H, Bignell GR, Cox C, Stephens P, Edkins S, Clegg S,
et al. Mutations of the BRAF gene in human cancer. Nature
2002;417:949–54.
6. Lynch TJ, Bell DW, Sordella R, Gurubhagavatula S, Okimoto RA,
Brannigan BW, et al. Activating mutations in the epidermal growth
factor receptor underlying responsiveness of non-small-cell lung cancer to gefitinib. N Engl J Med 2004;350:2129–39.
7. Paez JG, Janne PA, Lee JC, Tracy S, Greulich H, Gabriel S, et al. EGFR
mutations in lung cancer: correlation with clinical response to gefitinib therapy. Science 2004;304:1497–500.
8. Pao W, Miller V, Zakowski M, Doherty J, Politi K, Sarkaria I, et al.
EGF receptor gene mutations are common in lung cancers from
“never smokers” and are associated with sensitivity of tumors to gefitinib and erlotinib. Proc Natl Acad Sci U S A 2004;101:13306–11.
9. Yang XR, Chang-Claude J, Goode EL, Couch FJ, Nevanlinna H,
Milne RL, et al. Associations of breast cancer risk factors with tumor subtypes: a pooled analysis from the Breast Cancer Association
Consortium studies. J Natl Cancer Inst 2011;103:250–63.
10. Hamberg P, Bos MM, Braun HJ, Stouthard JM, van Deijk GA,
Erdkamp FL, et al. Randomized phase II study comparing efficacy
and safety of combination-therapy trastuzumab and docetaxel vs.
sequential therapy of trastuzumab followed by docetaxel alone at
progression as first-line chemotherapy in patients with HER2+
metastatic breast cancer: HERTAX trial. Clin Breast Cancer
2011;11:103–13.
11. Owens MA, Horten BC, Da Silva MM. HER2 amplification ratios
by fluorescence in situ hybridization and correlation with immunohistochemistry in a cohort of 6556 breast cancer tissues. Clin Breast
Cancer 2004;5:63–9.
12. Lee AH, Key HP, Bell JA, Hodi Z, Ellis IO. Breast carcinomas with
borderline (2+) HER2 immunohistochemistry: percentage of cells
with complete membrane staining for HER2 and the frequency of
HER2 amplification. J Clin Pathol 2011;64:490–2.
13. Buchdunger E, Cioffi CL, Law N, Stover D, Ohno-Jones S, Druker BJ,
et al. Abl protein-tyrosine kinase inhibitor STI571 inhibits in vitro
signal transduction mediated by c-kit and platelet-derived growth
factor receptors. J Pharmacol Exp Ther 2000;295:139–45.
14. Demetri GD, von Mehren M, Blanke CD, Van den Abbeele AD,
Eisenberg B, Roberts PJ, et al. Efficacy and safety of imatinib
SEPTEMBER 2011CANCER DISCOVERY | 307
Downloaded from cancerdiscovery.aacrjournals.org on June 18, 2017. © 2011 American Association for
Cancer Research.
7953_CD-11-0110_pp297-311.indd
307
8/30/11
3:19 PM
MacConaill et al.
REVIEW
SECTION
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
mesylate in advanced gastrointestinal stromal tumors. N Engl J Med
2002;347:472–80.
Heinrich MC, Corless CL, Blanke CD, Demetri GD, Joensuu H,
Roberts PJ, et al. Molecular correlates of imatinib resistance in gastrointestinal stromal tumors. J Clin Oncol 2006;24:4764–74.
Flaherty KT, Puzanov I, Kim KB, Ribas A, McArthur GA, Sosman
JA, et al. Inhibition of mutated, activated BRAF in metastatic melanoma. N Engl J Med 2010;363:809–19.
Chapman PB, Hauschild A, Robert C, Haanen JB, Ascierto P, Larkin
J, et al. Improved survival with vemurafenib in melanoma with BRAF
V600E mutation. N Engl J Med 2011;364:2507–16.
Burris HA, 3rd, Hurwitz HI, Dees EC, Dowlati A, Blackwell KL,
O’Neil B, et al. Phase I safety, pharmacokinetics, and clinical activity
study of lapatinib (GW572016), a reversible dual inhibitor of epidermal growth factor receptor tyrosine kinases, in heavily pretreated
patients with metastatic carcinomas. J Clin Oncol 2005;23:5305–13.
Khambata-Ford S, Garrett CR, Meropol NJ, Basik M, Harbison CT,
Wu S, et al. Expression of epiregulin and amphiregulin and K-ras
mutation status predict disease control in metastatic colorectal cancer patients treated with cetuximab. J Clin Oncol 2007;25:3230–7.
Jackman DM, Miller VA, Cioffredi LA, Yeap BY, Janne PA, Riely GJ, et
al. Impact of epidermal growth factor receptor and KRAS mutations
on clinical outcomes in previously untreated non-small cell lung
cancer patients: results of an online tumor registry of clinical trials.
Clin Cancer Res 2009;15:5267–73.
Loupakis F, Ruzzo A, Cremolini C, Vincenzi B, Salvatore L, Santini
D, et al. KRAS codon 61, 146 and BRAF mutations predict resistance
to cetuximab plus irinotecan in KRAS codon 12 and 13 wild-type
metastatic colorectal cancer. Br J Cancer 2009;101:715–21.
Van Cutsem E, Kohne CH, Hitre E, Zaluski J, Chang Chien CR,
Makhson A, et al. Cetuximab and chemotherapy as initial treatment
for metastatic colorectal cancer. N Engl J Med 2009;360:1408–17.
Mansour JC, Schwarz RE. Molecular mechanisms for individualized
cancer care. J Am Coll Surg 2008;207:250–8.
van’t Veer LJ, Bernards R. Enabling personalized cancer medicine
through analysis of gene-expression patterns. Nature 2008;452:564–70.
Yanagi M, Shinjo K, Takeshita A, Tobita T, Yano K, Kobayashi M,
et al. Simple and reliably sensitive diagnosis and monitoring of
Philadelphia chromosome-positive cells in chronic myeloid leukemia
by interphase fluorescence in situ hybridization of peripheral blood
cells. Leukemia 1999;13:542–52.
Reinhold U, Hennig E, Leiblein S, Niederwieser D, Deininger MW.
FISH for BCR-ABL on interphases of peripheral blood neutrophils but not of unselected white cells correlates with bone marrow cytogenetics in CML patients treated with imatinib. Leukemia
2003;17:1925–9.
Kallioniemi OP, Kallioniemi A, Kurisu W, Thor A, Chen LC, Smith
HS, et al. ERBB2 amplification in breast cancer analyzed by fluorescence in situ hybridization. Proc Natl Acad Sci U S A 1992;89:5321–5.
Kwak EL, Bang YJ, Camidge DR, Shaw AT, Solomon B, Maki RG,
et al. Anaplastic lymphoma kinase inhibition in non-small-cell lung
cancer. N Engl J Med 2010;363:1693–703.
Debiec-Rychter M, Sciot R, Le Cesne A, Schlemmer M, Hohenberger
P, van Oosterom AT, et al. KIT mutations and dose selection for imatinib in patients with advanced gastrointestinal stromal tumours.
Eur J Cancer 2006;42:1093–103.
Flaherty K, Puzanov I, Sosman J, Kim K, Ribas A, McArthur G, et al.
Phase I study of PLX4032: Proof of concept for V600E BRAF mutation
as a therapeutic target in human cancer. J Clin Oncol 2009;27:9000.
Wilhelm SM, Adnane L, Newell P, Villanueva A, Llovet JM, Lynch M.
Preclinical overview of sorafenib, a multikinase inhibitor that targets
both Raf and VEGF and PDGF receptor tyrosine kinase signaling.
Mol Cancer Ther 2008;7:3129–40.
Rosenwald A, Staudt LM. Clinical translation of gene expression profiling in lymphomas and leukemias. Semin Oncol 2002;29:258–63.
Rosenwald A, Staudt LM. Gene expression profiling of diffuse large
B-cell lymphoma. Leuk Lymphoma 2003;44 Suppl 3:S41–7.
Harris L, Fritsche H, Mennel R, Norton L, Ravdin P, Taube S,
et al. American Society of Clinical Oncology 2007 update of
308 | CANCER DISCOVERY SEPTEMBER 2011 35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
recommendations for the use of tumor markers in breast cancer. J
Clin Oncol 2007;25:5287–312.
van de Vijver MJ, He YD, van’t Veer LJ, Dai H, Hart AA, Voskuil DW,
et al. A gene-expression signature as a predictor of survival in breast
cancer. N Engl J Med 2002;347:1999–2009.
van ‘t Veer LJ, Dai H, van de Vijver MJ, He YD, Hart AA, Mao M, et al.
Gene expression profiling predicts clinical outcome of breast cancer.
Nature 2002;415:530–6.
Sanger F, Coulson AR. A rapid method for determining sequences
in DNA by primed synthesis with DNA polymerase. J Mol Biol
1975;94:441–8.
Pease AC, Solas D, Sullivan EJ, Cronin MT, Holmes CP, Fodor SP.
Light-generated oligonucleotide arrays for rapid DNA sequence analysis. Proc Natl Acad Sci U S A 1994;91:5022–6.
Ross P, Hall L, Smirnov I, Haff L. High level multiplex genotyping by
MALDI-TOF mass spectrometry. Nat Biotechnol 1998;16:1347–51.
Margulies M, Egholm M, Altman WE, Attiya S, Bader JS, Bemben LA,
et al. Genome sequencing in microfabricated high-density picolitre
reactors. Nature 2005;437:376–80.
Shendure J, Porreca GJ, Reppas NB, Lin X, McCutcheon JP,
Rosenbaum AM, et al. Accurate multiplex polony sequencing of an
evolved bacterial genome. Science 2005;309:1728–32.
Bentley DR, Balasubramanian S, Swerdlow HP, Smith GP, Milton J,
Brown CG, et al. Accurate whole human genome sequencing using
reversible terminator chemistry. Nature 2008;456:53–9.
Smith DR, Quinlan AR, Peckham HE, Makowsky K, Tao W, Woolf B,
et al. Rapid whole-genome mutational profiling using next-generation sequencing technologies. Genome Res 2008;18:1638–42.
Shendure J, Ji H. Next-generation DNA sequencing. Nat Biotechnol
2008;26:1135–45.
Pettersson E, Lundeberg J, Ahmadian A. Generations of sequencing
technologies. Genomics 2009;93:105–11.
Lander ES, Linton LM, Birren B, Nusbaum C, Zody MC, Baldwin J,
et al. Initial sequencing and analysis of the human genome. Nature
2001;409:860–921.
Venter JC, Adams MD, Myers EW, Li PW, Mural RJ, Sutton GG, et al.
The sequence of the human genome. Science 2001;291:1304–51.
Lander ES. Initial impact of the sequencing of the human genome.
Nature 2011;470:187–97.
Baxter EJ, Scott LM, Campbell PJ, East C, Fourouclas N, Swanton S,
et al. Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. Lancet 2005;365:1054–61.
Levine RL, Wadleigh M, Cools J, Ebert BL, Wernig G, Huntly BJ, et al.
Activating mutation in the tyrosine kinase JAK2 in polycythemia
vera, essential thrombocythemia, and myeloid metaplasia with myelofibrosis. Cancer Cell 2005;7:387–97.
Dutt A, Salvesen HB, Chen TH, Ramos AH, Onofrio RC, Hatton C,
et al. Drug-sensitive FGFR2 mutations in endometrial carcinoma.
Proc Natl Acad Sci U S A 2008;105:8713–7.
Chen Y, Takita J, Choi YL, Kato M, Ohira M, Sanada M, et al.
Oncogenic mutations of ALK kinase in neuroblastoma. Nature
2008;455:971–4.
George RE, Sanda T, Hanna M, Frohling S, Luther W, 2nd, Zhang
J, et al. Activating mutations in ALK provide a therapeutic target in
neuroblastoma. Nature 2008;455:975–8.
Samuels Y, Wang Z, Bardelli A, Silliman N, Ptak J, Szabo S, et al.
High frequency of mutations of the PIK3CA gene in human cancers.
Science 2004;304:554.
Ahn SM, Kim TH, Lee S, Kim D, Ghang H, Kim DS, et al. The first
Korean genome sequence and analysis: full genome sequencing for a
socio-ethnic group. Genome Res 2009;19:1622–9.
Wang J, Wang W, Li R, Li Y, Tian G, Goodman L, et al. The diploid
genome sequence of an Asian individual. Nature 2008;456:60–5.
Wheeler DA, Srinivasan M, Egholm M, Shen Y, Chen L, McGuire A,
et al. The complete genome of an individual by massively parallel
DNA sequencing. Nature 2008;452:872–6.
Levy S, Sutton G, Ng PC, Feuk L, Halpern AL, Walenz BP, et al.
The diploid genome sequence of an individual human. PLoS Biol
2007;5:e254.
www.aacrjournals.org
Downloaded from cancerdiscovery.aacrjournals.org on June 18, 2017. © 2011 American Association for
Cancer Research.
7953_CD-11-0110_pp297-311.indd
308
8/30/11
10:46 AM
Clinical Implementation of Cancer Genomes
59. Kim JI, Ju YS, Park H, Kim S, Lee S, Yi JH, et al. A highly annotated wholegenome sequence of a Korean individual. Nature 2009;460:1011–5.
60. Ley TJ, Mardis ER, Ding L, Fulton B, McLellan MD, Chen K, et al.
DNA sequencing of a cytogenetically normal acute myeloid leukaemia genome. Nature 2008;456:66–72.
61. Mardis ER, Ding L, Dooling DJ, Larson DE, McLellan MD, Chen K,
et al. Recurring mutations found by sequencing an acute myeloid
leukemia genome. N Engl J Med 2009;361:1058–66.
62. Campbell PJ, Stephens PJ, Pleasance ED, O’Meara S, Li H, Santarius
T, et al. Identification of somatically acquired rearrangements in cancer using genome-wide massively parallel paired-end sequencing. Nat
Genet 2008;40:722–9.
63. Pleasance ED, Stephens PJ, O’Meara S, McBride DJ, Meynert A, Jones
D, et al. A small-cell lung cancer genome with complex signatures of
tobacco exposure. Nature 2010;463:184–90.
64. Lee W, Jiang Z, Liu J, Haverty PM, Guan Y, Stinson J, et al. The mutation spectrum revealed by paired genome sequences from a lung
cancer patient. Nature 2010;465:473–7.
65. Ding L, Ellis MJ, Li S, Larson DE, Chen K, Wallis JW, et al. Genome
remodelling in a basal-like breast cancer metastasis and xenograft.
Nature 2010;464:999–1005.
66. Shah SP, Morin RD, Khattra J, Prentice L, Pugh T, Burleigh A, et al.
Mutational evolution in a lobular breast tumour profiled at single
nucleotide resolution. Nature 2009;461:809–13.
67. Stephens PJ, McBride DJ, Lin ML, Varela I, Pleasance ED, Simpson
JT, et al. Complex landscapes of somatic rearrangement in human
breast cancer genomes. Nature 2009;462:1005–10.
68. Pleasance ED, Cheetham RK, Stephens PJ, McBride DJ, Humphray
SJ, Greenman CD, et al. A comprehensive catalogue of somatic mutations from a human cancer genome. Nature 2010;463:191–6.
69. Chapman MA, Lawrence MS, Keats JJ, Cibulskis K, Sougnez C,
Schinzel AC, et al. Initial genome sequencing and analysis of multiple myeloma. Nature 2011;471:467–72.
70. Hudson TJ, Anderson W, Artez A, Barker AD, Bell C, Bernabe RR,
et al. International network of cancer genome projects. Nature
2010;464:993–8.
71. MacConaill LE, Campbell CD, Kehoe SM, Bass AJ, Hatton C, Niu
L, et al. Profiling critical cancer gene mutations in clinical tumor
samples. PLoS One 2009;4:e7887.
72. Thomas RK, Baker AC, Debiasi RM, Winckler W, Laframboise T, Lin
WM, et al. High-throughput oncogene mutation profiling in human
cancer. Nat Genet 2007;39:347–51.
73. Su Z, Dias-Santagata D, Duke M, Hutchinson K, Lin YL, Borger DR,
et al. A platform for rapid detection of multiple oncogenic mutations with relevance to targeted therapy in non-small-cell lung cancer. J Mol Diagn 2011;13:74–84.
74. Dias-Santagata D, Akhavanfard S, David SS, Vernovsky K, Kuhlmann
G, Boisvert SL, et al. Rapid targeted mutational analysis of human
tumours: a clinical platform to guide personalized cancer medicine.
EMBO Mol Med 2010;2:146–58.
75. Arcila M, Lau C, Nafa K, Ladanyi M. Detection of KRAS and BRAF
mutations in colorectal carcinoma roles for high-sensitivity locked
nucleic acid-PCR sequencing and broad-spectrum mass spectrometry genotyping. J Mol Diagn 2011;13:64–73.
76. Lau C, Ang D, Brzostowski EB, Riely GJ, Rusch VR, Zakowski
MF. LC-MAP: a pilot study of prospective profiling of clinical
tumor specimens for the presence of key mutations in targetable pathways in patients with lung adenocarcinoma and metastatic colorectal cancer using Sequenom genotyping. J Mol Diagn
2010;12:910.
77. Arcila M, Lau CY, Jhanwar SC, Zakowski MF, Kris MG, Ladanyi
M. Comprehensive analysis for clinically relevant oncogenic driver
mutations in 1131 consecutive lung adenocarcinomas. Mod Pathol
2011;24:404a.
78. Gonzalez-Angulo AM, Hennessy BT, Mills GB. Future of personalized medicine in oncology: a systems biology approach. J Clin Oncol
2010;28:2777–83.
79. Beadling C, Heinrich MC, Warrick A, Forbes EM, Nelson D,
Justusson E, et al. Multiplex mutation screening by mass
REVIEW
80.
81.
82.
83.
84.
85.
86.
87.
88.
89.
90.
91.
92.
93.
94.
95.
96.
97.
98.
99.
spectrometry: evaluation of 820 cases from a personalized cancer
medicine registry. J Mol Diagn 2011. Epub 2011 Jul 1.
Gilbert MT, Haselkorn T, Bunce M, Sanchez JJ, Lucas SB, Jewell LD,
et al. The isolation of nucleic acids from fixed, paraffin-embedded
tissues—which methods are useful when? PLoS One 2007;2:e537.
Gallegos Ruiz MI, Floor K, Rijmen F, Grunberg K, Rodriguez JA,
Giaccone G. EGFR and K-ras mutation analysis in non-small cell
lung cancer: comparison of paraffin embedded versus frozen specimens. Cell Oncol 2007;29:257–64.
Srinivasan M, Sedmak D, Jewell S. Effect of fixatives and tissue processing on the content and integrity of nucleic acids. Am J Pathol
2002;161:1961–71.
Wood HM, Belvedere O, Conway C, Daly C, Chalkley R, Bickerdike
M, et al. Using next-generation sequencing for high resolution multiplex analysis of copy number variation from nanogram quantities
of DNA from formalin-fixed paraffin-embedded specimens. Nucleic
Acids Res 2010;38:e151.
Navin N, Krasnitz A, Rodgers L, Cook K, Meth J, Kendall J, et al.
Inferring tumor progression from genomic heterogeneity. Genome
Res 2010;20:68–80.
Jones S, Chen WD, Parmigiani G, Diehl F, Beerenwinkel N, Antal T,
et al. Comparative lesion sequencing provides insights into tumor
evolution. Proc Natl Acad Sci U S A 2008;105:4283–8.
O’Hare T, Eide CA, Deininger MW. Bcr-Abl kinase domain mutations, drug resistance, and the road to a cure for chronic myeloid
leukemia. Blood 2007;110:2242–9.
Pao W, Miller VA, Politi KA, Riely GJ, Somwar R, Zakowski MF,
et al. Acquired resistance of lung adenocarcinomas to gefitinib or
erlotinib is associated with a second mutation in the EGFR kinase
domain. PLoS Med 2005;2:e73.
Antonescu CR, Besmer P, Guo T, Arkun K, Hom G, Koryotowski
B, et al. Acquired resistance to imatinib in gastrointestinal stromal
tumor occurs through secondary gene mutation. Clin Cancer Res
2005;11:4182–90.
Emery CM, Vijayendran KG, Zipser MC, Sawyer AM, Niu L, Kim JJ, et
al. MEK1 mutations confer resistance to MEK and B-RAF inhibition.
Proc Natl Acad Sci U S A 2009;106:20411–6.
Kwak EL, Sordella R, Bell DW, Godin-Heymann N, Okimoto RA,
Brannigan BW, et al. Irreversible inhibitors of the EGF receptor may
circumvent acquired resistance to gefitinib. Proc Natl Acad Sci U S A
2005;102:7665–70.
Thomas RK, Nickerson E, Simons JF, Janne PA, Tengs T, Yuza Y,
et al. Sensitive mutation detection in heterogeneous cancer specimens by massively parallel picoliter reactor sequencing. Nat Med
2006;12:852–5.
Kallioniemi A, Kallioniemi OP, Sudar D, Rutovitz D, Gray JW,
Waldman F, et al. Comparative genomic hybridization for molecular
cytogenetic analysis of solid tumors. Science 1992;258:818–21.
Van Buggenhout G, Melotte C, Dutta B, Froyen G, Van Hummelen
P, Marynen P, et al. Mild Wolf-Hirschhorn syndrome: micro-array
CGH analysis of atypical 4p16.3 deletions enables refinement of the
genotype-phenotype map. J Med Genet 2004;41:691–8.
Oeth P, del Mistro G, Marnellos G, Shi T, van den Boom D. Qualitative
and quantitative genotyping using single base primer extension coupled with matrix-assisted laser desorption/ionization time-of-flight
mass spectrometry (MassARRAY). Methods Mol Biol 2009;578:307–43.
Ehrlich KC, Montalbano BG, Cotty PJ. Analysis of single nucleotide
polymorphisms in three genes shows evidence for genetic isolation
of certain Aspergillus flavus vegetative compatibility groups. FEMS
Microbiol Lett 2007;268:231–6.
Meyerson M, Gabriel S, Getz G. Advances in understanding cancer genomes through second-generation sequencing. Nat Rev Genet
2010;11:685–96.
Mardis ER. ChIP-seq: welcome to the new frontier. Nat Methods
2007;4:613–4.
Wang Z, Gerstein M, Snyder M. RNA-Seq: a revolutionary tool for
transcriptomics. Nat Rev Genet 2009;10:57–63.
Consortium M, Shi L, Reid LH, Jones WD, Shippy R, Warrington
JA, et al. The MicroArray Quality Control (MAQC) project shows
SEPTEMBER 2011 CANCER DISCOVERY | 309
Downloaded from cancerdiscovery.aacrjournals.org on June 18, 2017. © 2011 American Association for
Cancer Research.
7953_CD-11-0110_pp297-311.indd
309
8/30/11
10:46 AM
MacConaill et al.
REVIEW
SECTION
inter- and intraplatform reproducibility of gene expression measurements. Nat Biotechnol 2006;24:1151–61.
100.Quail MA, Swerdlow H, Turner DJ. Improved protocols for the illumina genome analyzer sequencing system. Curr Protoc Hum Genet
2009;Chapter 18:Unit 18 2.
101.Lennon NJ, Lintner RE, Anderson S, Alvarez P, Barry A, Brockman
W, et al. A scalable, fully automated process for construction of sequence-ready barcoded libraries for 454. Genome Biol 2010;11:R15.
102.Albert TJ, Molla MN, Muzny DM, Nazareth L, Wheeler D, Song X,
et al. Direct selection of human genomic loci by microarray hybridization. Nat Methods 2007;4:903–5.
103.Hodges E, Xuan Z, Balija V, Kramer M, Molla MN, Smith SW, et al.
Genome-wide in situ exon capture for selective resequencing. Nat
Genet 2007;39:1522–7.
104.Porreca GJ, Zhang K, Li JB, Xie B, Austin D, Vassallo SL, et al.
Multiplex amplification of large sets of human exons. Nat Methods
2007;4:931–6.
105.Gnirke A, Melnikov A, Maguire J, Rogov P, LeProust EM, Brockman
W, et al. Solution hybrid selection with ultra-long oligonucleotides for massively parallel targeted sequencing. Nat Biotechnol
2009;27:182–9.
106.Wagle N, Emery C, Berger MF, Davis MJ, Sawyer A, Pochanard P,
et al. Dissecting therapeutic resistance to RAF inhibition in melanoma by tumor genomic profiling. J Clin Oncol 2011;29:3085–96.
107.Maher CA, Palanisamy N, Brenner JC, Cao X, Kalyana-Sundaram S,
Luo S, et al. Chimeric transcript discovery by paired-end transcriptome sequencing. Proc Natl Acad Sci U S A 2009;106:12353–8.
108.Maher CA, Kumar-Sinha C, Cao X, Kalyana-Sundaram S, Han B, Jing
X, et al. Transcriptome sequencing to detect gene fusions in cancer.
Nature 2009;458:97–101.
109.Morrissy AS, Morin RD, Delaney A, Zeng T, McDonald H, Jones S,
et al. Next-generation tag sequencing for cancer gene expression profiling. Genome Res 2009;19:1825–35.
110.Alkan C, Kidd JM, Marques-Bonet T, Aksay G, Antonacci F,
Hormozdiari F, et al. Personalized copy number and segmental
duplication maps using next-generation sequencing. Nat Genet
2009;41:1061–7.
111.McKenna A, Hanna M, Banks E, Sivachenko A, Cibulskis K,
Kernytsky A, et al. The Genome Analysis Toolkit: a MapReduce
framework for analyzing next-generation DNA sequencing data.
Genome Res 2010;20:1297–303.
112.Kim H, Kim J, Selby H, Gao D, Tong T, Phang TL, et al. A short survey of computational analysis methods in analysing ChIP-seq data.
Hum Genomics 2011;5:117–23.
113.Cancer Genome Atlas Research N. Comprehensive genomic characterization defines human glioblastoma genes and core pathways.
Nature 2008;455:1061–8.
114.Schreiber SL, Shamji AF, Clemons PA, Hon C, Koehler AN, Munoz
B, et al. Towards patient-based cancer therapeutics. Nat Biotechnol
2010;28:904–6.
115.Curtin JA, Busam K, Pinkel D, Bastian BC. Somatic activation of KIT
in distinct subtypes of melanoma. J Clin Oncol 2006;24:4340–6.
116.Hodi FS, Friedlander P, Corless CL, Heinrich MC, Mac Rae S, Kruse
A, et al. Major response to imatinib mesylate in KIT-mutated melanoma. J Clin Oncol 2008;26:2046–51.
117.Lutzky J, Bauer J, Bastian BC. Dose-dependent, complete response
to imatinib of a metastatic mucosal melanoma with a K642E KIT
mutation. Pigment Cell Melanoma Res 2008;21:492–3.
118.Janku F, Tsimberidou AM, Garrido-Laguna I, Wang X, Luthra R,
Hong DS, et al. PIK3CA mutations in patients with advanced cancers treated with PI3K/AKT/mTOR axis inhibitors. Mol Cancer Ther
2011;10:558–65.
119.Ashworth A, Lord CJ, Reis-Filho JS. Genetic interactions in cancer
progression and treatment. Cell 2011;145:30–8.
120.Heidorn SJ, Milagre C, Whittaker S, Nourry A, Niculescu-Duvas I,
Dhomen N, et al. Kinase-dead BRAF and oncogenic RAS cooperate
to drive tumor progression through CRAF. Cell 2010;140:209–21.
121.Carracedo A, Ma L, Teruya-Feldstein J, Rojo F, Salmena L, Alimonti
A, et al. Inhibition of mTORC1 leads to MAPK pathway activation
310 | CANCER DISCOVERY SEPTEMBER 2011 through a PI3K-dependent feedback loop in human cancer. J Clin
Invest 2008;118:3065–74.
122.Hoeflich KP, O’Brien C, Boyd Z, Cavet G, Guerrero S, Jung K, et al.
In vivo antitumor activity of MEK and phosphatidylinositol 3-kinase inhibitors in basal-like breast cancer models. Clin Cancer Res
2009;15:4649–64.
123.Ashworth A. Drug resistance caused by reversion mutation. Cancer
Res 2008;68:10021–3.
124.Engelman JA, Zejnullahu K, Mitsudomi T, Song Y, Hyland C, Park
JO, et al. MET amplification leads to gefitinib resistance in lung cancer by activating ERBB3 signaling. Science 2007;316:1039–43.
125.Gorre ME, Mohammed M, Ellwood K, Hsu N, Paquette R, Rao PN,
et al. Clinical resistance to STI-571 cancer therapy caused by BCRABL gene mutation or amplification. Science 2001;293:876–80.
126.Daub H, Specht K, Ullrich A. Strategies to overcome resistance to targeted protein kinase inhibitors. Nat Rev Drug Discov
2004;3:1001–10.
127.Poulikakos PI, Zhang C, Bollag G, Shokat KM, Rosen N. RAF inhibitors transactivate RAF dimers and ERK signalling in cells with wildtype BRAF. Nature 2010;464:427–30.
128.Hatzivassiliou G, Song K, Yen I, Brandhuber BJ, Anderson DJ,
Alvarado R, et al. RAF inhibitors prime wild-type RAF to activate the
MAPK pathway and enhance growth. Nature 2010;464:431–5.
129.Johannessen CM, Boehm JS, Kim SY, Thomas SR, Wardwell L,
Johnson LA, et al. COT drives resistance to RAF inhibition through
MAP kinase pathway reactivation. Nature 2010;468:968–72.
130.Maheswaran S, Sequist LV, Nagrath S, Ulkus L, Brannigan B, Collura
CV, et al. Detection of mutations in EGFR in circulating lung-cancer
cells. N Engl J Med 2008;359:366–77.
131.Paterlini-Brechot P, Benali NL. Circulating tumor cells (CTC)
detection: clinical impact and future directions. Cancer Lett
2007;253:180–204.
132.Nagrath S, Sequist LV, Maheswaran S, Bell DW, Irimia D, Ulkus L,
et al. Isolation of rare circulating tumour cells in cancer patients by
microchip technology. Nature 2007;450:1235–9.
133.Leary RJ, Kinde I, Diehl F, Schmidt K, Clouser C, Duncan C, et al.
Development of personalized tumor biomarkers using massively parallel sequencing. Sci Transl Med 2010;2:20ra14.
134.Brevet M, Johnson ML, Azzoli CG, Ladanyi M. Detection of EGFR
mutations in plasma DNA from lung cancer patients by mass
spectrometry genotyping is predictive of tumor EGFR status and
response to EGFR inhibitors. Lung Cancer 2011;73:96–102.
135.McBride DJ, Orpana AK, Sotiriou C, Joensuu H, Stephens PJ, Mudie
LJ, et al. Use of cancer-specific genomic rearrangements to quantify
disease burden in plasma from patients with solid tumors. Genes
Chromosomes Cancer 2010;49:1062–9.
136.Riethdorf S, Muller V, Zhang L, Rau T, Loibl S, Komor M, et al.
Detection and HER2 expression of circulating tumor cells: prospective monitoring in breast cancer patients treated in the neoadjuvant
GeparQuattro trial. Clin Cancer Res 2010;16:2634–45.
137.Navin N, Kendall J, Troge J, Andrews P, Rodgers L, McIndoo J,
et al. Tumour evolution inferred by single-cell sequencing. Nature
2011;472:90–4.
138.Corless CL, McGreevey L, Haley A, Town A, Heinrich MC. KIT mutations are common in incidental gastrointestinal stromal tumors one
centimeter or less in size. Am J Pathol 2002;160:1567–72.
139.de Jong FA, Verweij J. Role of imatinib mesylate (Gleevec/Glivec)
in gastrointestinal stromal tumors. Expert Rev Anticancer Ther
2003;3:757–66.
140.Verweij J, van Oosterom A, Blay JY, Judson I, Rodenhuis S, van der
Graaf W, et al. Imatinib mesylate (STI-571 Glivec, Gleevec) is an active agent for gastrointestinal stromal tumours, but does not yield
responses in other soft-tissue sarcomas that are unselected for a
molecular target. Results from an EORTC Soft Tissue and Bone
Sarcoma Group phase II study. Eur J Cancer 2003;39:2006–11.
141.Gandhi J, Zhang J, Xie Y, Soh J, Shigematsu H, Zhang W, et al.
Alterations in genes of the EGFR signaling pathway and their relationship to EGFR tyrosine kinase inhibitor sensitivity in lung cancer
cell lines. PLoS One 2009;4:e4576.
www.aacrjournals.org
Downloaded from cancerdiscovery.aacrjournals.org on June 18, 2017. © 2011 American Association for
Cancer Research.
7953_CD-11-0110_pp297-311.indd
310
8/30/11
10:46 AM
Clinical Implementation of Cancer Genomes
142.Soda M, Choi YL, Enomoto M, Takada S, Yamashita Y, Ishikawa S,
et al. Identification of the transforming EML4-ALK fusion gene in
non-small-cell lung cancer. Nature 2007;448:561–6.
143.Palanisamy N, Ateeq B, Kalyana-Sundaram S, Pflueger D,
Ramnarayanan K, Shankar S, et al. Rearrangements of the RAF kinase pathway in prostate cancer, gastric cancer and melanoma. Nat
Med 2010;16:793–8.
144.Karasarides M, Chiloeches A, Hayward R, Niculescu-Duvaz D,
Scanlon I, Friedlos F, et al. B-RAF is a therapeutic target in melanoma. Oncogene 2004;23:6292–8.
145.Wilhelm SM, Carter C, Tang L, Wilkie D, McNabola A, Rong H,
et al. BAY 43-9006 exhibits broad spectrum oral antitumor activity and targets the RAF/MEK/ERK pathway and receptor tyrosine
kinases involved in tumor progression and angiogenesis. Cancer Res
2004;64:7099–109.
146.Wan PT, Garnett MJ, Roe SM, Lee S, Niculescu-Duvaz D, Good VM,
et al. Mechanism of activation of the RAF-ERK signaling pathway by
oncogenic mutations of B-RAF. Cell 2004;116:855–67.
147.Eisen T, Ahmad T, Flaherty KT, Gore M, Kaye S, Marais R, et al.
Sorafenib in advanced melanoma: a Phase II randomised discontinuation trial analysis. Br J Cancer 2006;95:581–6.
148.Kane RC, Farrell AT, Saber H, Tang S, Williams G, Jee JM, et al.
Sorafenib for the treatment of advanced renal cell carcinoma. Clin
Cancer Res 2006;12:7271–8.
149.Lang L. FDA approves sorafenib for patients with inoperable liver
cancer. Gastroenterology 2008;134:379.
150.Algazi AP, Soon CW, Daud AI. Treatment of cutaneous melanoma:
current approaches and future prospects. Cancer Manag Res
2010;2:197-211.
151.Whittaker S, Kirk R, Hayward R, Zambon A, Viros A, Cantarino
N, et al. Gatekeeper mutations mediate resistance to BRAF-targeted
therapies. Sci Transl Med 2010;2:35ra41.
REVIEW
152.O’Connell MJ, Lavery I, Yothers G, Paik S, Clark-Langone KM,
Lopatin M, et al. Relationship between tumor gene expression and
recurrence in four independent studies of patients with stage II/III
colon cancer treated with surgery alone or surgery plus adjuvant
fluorouracil plus leucovorin. J Clin Oncol 2010;28:3937–44.
153.Mok TS, Wu YL, Thongprasert S, Yang CH, Chu DT, Saijo N, et al.
Gefitinib or carboplatin-paclitaxel in pulmonary adenocarcinoma. N
Engl J Med 2009;361:947–57.
154.Douillard JY, Shepherd FA, Hirsh V, Mok T, Socinski MA, Gervais
R, et al. Molecular predictors of outcome with gefitinib and
docetaxel in previously treated non-small-cell lung cancer: data
from the randomized phase III INTEREST trial. J Clin Oncol
2010;28:744–52.
155.Haber DA, Gray NS, Baselga J. The evolving war on cancer. Cell
2011;145:19–24.
156.Yap TA, Sandhu SK, Workman P, de Bono JS.Envisioning the
future of early anticancer drug development. Nat Rev Cancer
2010;10:514–23.
157.McDermott U, Downing JR, Stratton MR. Genomics and the continuum of cancer care. N Engl J Med 2011;364:340–50.
158.de Bono JS, Ashworth A. Translating cancer research into targeted
therapeutics. Nature 2010;467:543–9.
159.Ullman-Cullere MH, Mathew JP. Emerging landscape of genomics in
the Electronic Health Record for personalized medicine. Hum Mutat
2011;32:512–6.
160.Clark L, Garrett PE, Martin R, Meier KL. User protocol for evaluation of qualitative test performances; approval guidelines. NCCLS
document EP12-A. Wayne (PA): Clinical and Laboratory Standards
Institute (CLIS); 2002.
161.Hinman LM, Carl KM, Spear BB, Salerno RA, Becker RL, Abbott BM,
et al. Development and regulatory strategies for drug and diagnostic
co-development. Pharmacogenomics 2010;11:1669–75.
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Clinical Implementation of Comprehensive Strategies to
Characterize Cancer Genomes: Opportunities and
Challenges
Laura E. MacConaill, Paul Van Hummelen, Matthew Meyerson, et al.
Cancer Discovery 2011;1:297-311.
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