Download Research Presentation on Thyroid Cancer

Research Presentation
Jason M. Leibowitz, MD
June 25, 2009
Preceptor: Marcia S. Brose, MD PhD
Otorhinolaryngology: Head and Neck Surgery at PENN
Excellence in Patient Care, Education and Research since 1870
Overview
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Background
Hypothesis
Methods
Results
Discussion
Conclusions & Future Directions
Thyroid Cancer in the United States
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Thyroid cancer is the most
common endocrine neoplasm.
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Thyroid cancer will be diagnosed
in 33,550 individuals (8070 men
and 25,480 women) this year.
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From 1997-2004 incidence of
thyroid cancer increased by 6.2%
mostly due to increased detection.
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From 1985 to 2004 mortality rate
increased by 0.3% a year.
RAI-Refractory Disease
 25-50% of metastatic thyroid cancers lose ability
to take up Iodine.
 Iodine Uptake inversely correlates with survival.
 This is attributed to down regulation of the Na+/ISymporter (NIS).
 Limited treatment options for unresectable
thyroid cancer refractory to RAI.
Molecular Changes in Thyroid Cancer
Molecular Pathway involved in
Thyroid Cancer
 Activation of MAPK
pathway
 Oncogenic activation
of this pathway in 70%
of all thyroid cancers.
 BRAF is a serine
threonine kinase
Xing, 2007.
BRAF V600E in Thyroid Cancer
V600E
2003: The BRAF V600E mutation is the most
common genetic alteration in thyroid cancer,
occurring in about 45% of sporadic papillary
thyroid cancers (PTCs).
BRAF V600E
 Point mutation in 40-45% of
PTC
 Upregulation of MMP, VEGF -->
invasion, angiogenesis
 Silencing of tumor suppressive
genes, genes involved in iodine
transport
 BRAF mutation associated with
multiple negative prognostic
indicators.
RAS
 Family of small G-proteins involved in transduction of
cellular signals from the cell membrane.
 Mutations in RAS gene lead to inappropriate activation
with constitutively activated downstream pathways and
also promote chromosomal instability.
 20% FTC contain a RAS mutation RAS mutations may
correlate with aggressive behavior (tumor dedifferentiation
and poorer prognosis).
Targeted Therapy in Thyroid
cancer
 Loss of differentiation (inability to trap RAI),
unresectable lesion, leads to poor prognosis
 BRAF inhibitors
 BAY 43-9006 (Sorafenib)
 Multikinase inhibitor
Sorafenib
 Orally active multikinase inhibitor (study
dose 400mg BID).
 Monoclonal antibody with multiple targets
including BRAF, VEGFR1, VEGFR2.
 Blocks tumor cell proliferation and
angiogenesis.
 FDA approved for treatment of RCC and
hepatocellular carcinoma.
Targeted Therapy and Genotype
 K-RAS gene mutation and metastatic colorectal carcinoma.
 Recent results from Phase II & III clinical trials demonstrate
that patients with metastatic colorectal cancer benefit from
anti-EGFR therapy.
 Patients with K-RAS mutation in codon 12 & 13 should not
receive anti-EGFR therapy since they do not receive any
benefit.
 EGFR and non-small cell lung cancer:
 Epithelial growth factor receptor
 10% mutated in NSCLC
 EGFR mutations are predictors of TKIs responsiveness and
may show a long lasting response to TKIs
 EXON 19 Deletion respond better to TKIs.
Prior Data
84 weeks
N=43
N= 52
WDTC
Papillary vs. Follicular
FTC = 19
P<0.095
PTC= 24
Prior Data
 Conclusions from prior data:
 Improved PFS with Sorafenib.
 Improved PFS of FTC treated with Sorafenib
when compared to PTC.
Overview
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Background
Hypothesis
Methods
Results
Discussion
Conclusions & Future Directions
Hypothesis
 There are specific genotypes (i.e. BRAF
V600E, RAS mutations) that predict
favorable response to targeted therapy
(Sorafenib).
Null Hypothesis
 Specific genetic mutations do not predict
response to targeted therapy in thyroid
cancer.
Overview
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Background
Hypothesis
Methods
Results
Discussion
Conclusions & Future Directions
Research Plan
 Tissue samples collected from patients with
treatment-resistant thyroid cancer with long term
follow-up (approximately 30 patients).
 All patients received targeted therapy (Sorafenib).
 Samples with WDTC analyzed for mutations in
BRAF and RAS genes when available:
 BRAF - V600E
 RAS - Exon 12, 13, 61
RESULTS
Sequence Output
 Computer program interprets
data and produces an
electropherogram, (aka trace)
 Each peak represents a base:
 A = Adenosine
 T = Thymine
 C = Cytosine
 G = Guanine
 N = Reading cannot be
determined
Overview
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Background
Hypothesis
Methods
Results
Discussion
Conclusions & Future Directions
Results of Stage 1 Analysis
•N= 30
•M = F = 15
•PTC=17, FTC= 9, Other (ATC/PD, MTC): 4
•Samples analyzed for BRAF mutation:
• 23/30 (76.6%): samples analyzed for BRAF mutation
• 4/30 (13%): definite genotype but questioned due to
phenotype (ATC/PD, MTC)
• 2/30 (6%): unable to amplify DNA despite multiple
PCR attempts
• 1/30 (3%): pending analysis
•18/30 samples analyzed for RAS mutation, all WT copies
of the gene
Results of Stage 1 Analysis
 N=22 (interim analysis)
 13 WT BRAF
 9 BRAF V600E
 16 PTC
 9 WT BRAF, 7 V600E
 6 FTC
 4 WT BRAF, 2 V600E
BRAF V600E
P<0.02
N=13
(WT=8,
V600E=5)
Updated genetics
 In our expanded
analysis to 22 pts with
WDTC, the effect is no
longer significant but
the trend exists.
 We are further
investigating BRAF
copy number in these
patients
N =22
WT = 13
BRAF V600E = 9
p=NS
Overview
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Background
Hypothesis
Methods
Results
Discussion
Conclusions & Future Directions
BRAFV600E Correlates with worse Survival
Elisei et. al, J Clin Endocrinol Metab, October 2008, 93(10):3943–3949
BRAFV600E Correlates with worse Survival
State of the mutation in PTC, 10/2008
THE BRAF connection
Ciampi et al. 2005
Updated genetics
 In our expanded
analysis to 22 pts with
WDTC, the effect is no
longer significant but
the trend exists.
 We are further
investigating BRAF
copy number in these
patients
N =22
WT = 13
BRAF V600E = 9
p=NS
BRAF (red) x 3
7 centromere (green) x 3
BRAF x4
7 centromere x4
4 copies each
3 copies each
THE BRAF connection!
Positive Predictor!
Ciampi et al,
2005.
Future Directions
 Completion of genotyping analysis of all
patients
 Evaluation of copy number gains in WDTC
 Hypothesis: Copy number gain accounts for
improved survival in FTC treated with
Sorafenib
 Null: Copy number gain does not influence
survival in FTC
Selected Sources
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Ciampi R, Zhu Z, Nikiforov YE. BRAF copy number gain in thyroid tumors detected by
fluorescence in situ hybridization. Endocrine Pathology 2005; 16(2): 99-105.
Ciampi R, Nikiforov YE. Alterations of the BRAF gene in thyroid tumors. Endocrine
Pathology 2005; 16:3): 163-171.
Gupta-Abramson V, Troxel AB, Nellore A, et al. Phase II Trial of Sorafenib in
Advanced Thyroid Cancer. Journal Clin Onc 2008; 26 (29): 4714-4719.
Kundra P, Burman KD. Thyroid Cancer Molecular Signaling Pathways and Use of
Targeted Therapy. Endoc Metab Clin N Am 2007;36: 839-853
Murer B. Targeted Therapy in Non-Small Cell Lung Cancer. Arch Path Lab Med. 2008;
132: 1573-1575.
Nikiforov YE. Thyroid Carcinoma: Molecular Pathways and Therapeutic targets.
Modern Pathology 2008; 21: S37-S43.
Vasko V, Ferrand M, Cristofaro JD et al. Specific Pattern of RAS Oncogene Mutations
in Follicular Thyroid Tumors. J. Clin Endocrin. & Metab. 2003; 88(6):2745-2752.
Xing M. BRAF Mutation in Papillary Thyroid Cancer: Pathogenic Role, Molecular
Basis, and Clinical Implication. End Rev 2007; 28(7): 742-762.
Thanks
 Marcia Brose, MD PhD
 Cathy Ma MD, PhD
 Kanchan Puttaswamy, MS