Download TNM Staging System

A Pictorial Guide to the Revised Staging
System for Non-Small Cell Lung Cancer
Through the Use of PET/CT
Bruno P. Soares, MD; Katherine Zukotynski, MD;
Mizuki Nishino, MD; Annick Van Den Abbeele, MD
Department of Imaging
Dana-Farber Cancer Institute
Disclosure of Commercial Interest
The authors do not have a financial relationship
with a commercial organization that may have
direct or indirect interest in the content of this
exhibit.
OBJECTIVE
To illustrate the changes to the staging system for
non-small cell lung cancer through the use of
PET/CT and to discuss the rationale behind these
changes.
Contents
• Epidemiology of lung cancer
• PET/CT in lung cancer staging
• Changes in the TNM classification system
Epidemiology of Lung Cancer
• Second most common malignancy and the leading cause
of cancer death for both men and women
• In 2009, there were an estimated 219,440 new cases of
lung cancer and an estimated 159,390 deaths from lung
cancer in the US
• Direct medical cost for treatment of lung cancer is
approximately $5 billion annually
• Smoking is responsible for 87% of lung cancer deaths
Reference:
American Cancer Society, Surveillance and Health Policy Research, 2009.
Contents
• Epidemiology of lung cancer
• PET/CT in lung cancer staging
• Changes in the TNM classification system
What is the TNM staging system?
What is the TNM staging system?
• T: extent of primary tumor
(size and involvement of contiguous structures)
• N: extent of involvement of regional lymph nodes
• M: extent of spread to distant sites
Why use TNM staging?
Why use TNM staging?
– Survival is heavily dependent on TNM tumor stage
– Stages IA - IIIB are dependant on T and N classification
– Stage IV disease is defined by metastatic disease
Role of PET/CT in T Staging
• Defining extent of invasion of adjacent structures
• Distinguishing tumor from atelectasis
• Evaluating additional pulmonary nodules
• Identification of malignant pleural effusions
Role of PET/CT in N Staging
• Evaluates the entire mediastinum (unlike mediastinoscopy)
• Relies on metabolic activity (unlike CT)
• Changes N staging in ~ 20% of cases, due to its ability to:
– Detect tumor in anatomically normal lymph nodes
– Exclude tumor involvement in enlarged lymph nodes
Limitations of PET/CT in N Staging
• Micrometastases in normal-sized lymph nodes
may not be detected
• Negative predictive value decreases depending on:
– Size of metastatic deposits
– Avidity of the primary tumor
Role of PET/CT in M Staging
The strength of FDG-PET is M staging!
– Improved detection of metastasis
– May reduce futile intervention
Contents
• Epidemiology of lung cancer
• PET/CT in lung cancer staging
• Changes in the TNM classification system
Background
• Limitations of the AJCC Cancer Staging Manual 6th ed:
• Based essentially on a single institution series
• Limited number of patients (small subgroups)
• Weighted toward surgically treated patients
• Since the 6th edition in 2002, there have been refinements
to the techniques available for clinical staging, especially
computed tomography (CT) and positron emission
tomography (PET)
Rationale for Changes (1)
Expansion of database of patients treated for lung cancer:
• 81,015 cases from 46 sources in over 19 countries
diagnosed between 1990 and 2000
• Treated by all modalities of care
• 41% surgery only
• 23% chemotherapy only
• 11% radiotherapy only
• 25% combined modalities
Rationale for Changes (2)
• The major determinant for development of
subgroups of T, N and M descriptors was the
outcome measure of overall survival
• Proposed changes to the TNM staging system
were externally validated against the Surveillance,
Epidemiology and End Results (SEER) database
from the same time period
Histologic Classification of Lung Tumors
–Non-small cell carcinoma (NSCLC)
» Squamous cell carcinoma
Unlike the
prior edition, which was
» Adenocarcinoma
validated only for NSCLC...
» Large cell carcinoma
The new TNM staging system includes
cell carcinoma
small –Small
cell carcinoma
and carcinoid tumors
–Carcinoid tumor
–Other rare types
TNM Staging 7th Edition: Summary of Changes
•
TNM staging system now also includes small cell carcinomas and carcinoid tumors of the lung
•
T classifications have been redefined:
•
T1 has been divided into T1a (≤2 cm in size) and T1b (>2-3 cm in size)
•
T2 has been divided into T2a (>3-5 cm in size) and T2b (>5-7 cm in size)
•
T2 (>7 cm in size) has been reclassified as T3
•
Multiple tumor nodules in the same lobe have been reclassified from T4 to T3
•
Multiple tumor nodules in the same lung but in a different lobe have been reclassified from M1 to T4
•
No changes in the N classification
•
M classifications have been redefined:
•
M1 has been divided into M1a and M1b
•
Malignant pleural and pericardial effusions have been reclassified from T4 to M1a
•
Separate tumor nodules in the contralateral lung are considered M1a
•
Distant metastases are considered M1b
Looks confusing?
So let’s describe and illustrate
the changes step by step...
TNM Staging 7th Edition: Changes in T Staging
• T1: Smaller than 3cm
•
T1a: less than or equal to 2cm;
The size threshold of •3 cm
was
confirmed
beor
a significant
T1b:
>2cm
and
less to
than
to 3cm
There was a significant difference
in
prognosis
forequal
lesions
cutpoint
retained
in the
of T1than
vs. T2
tumor.
less thanand
2 cm
compared
to definition
lesions larger
2 cm
• T2: >3cm
or Involves
the
main bronchus,
2 cm or more distal
(cutpoint),
generating
subgroups
T1a and T1b.
to the carina or invades the visceral pleura, or with atelectasis
extending to the hilum
TNM Staging 7th Edition: Changes in T Staging
• T1a: less than or equal to 2 cm
• T1b: >2cm and less than or equal to 3 cm
• T2a: >3cm and less than or equal to 5 cm
• T2b: >5cm and less than or equal to 7 cm
• T3: >7 cm
Significant cutpoints were identified at 5 and 7 cm,
generating new subgroups.
Example: 9 mm nodule
T1a: less than or equal to 2cm (previously T1)
Example: 2,2 cm nodule
T1b: >2cm and less than or equal to 3cm (previously T1)
Example: 6,4 cm mass
T2a: >3cm and less than or equal to 5 cm
T2b: >5cm and less than or equal to 7cm
T3: >7cm
(previously any tumor larger than 3 cm was considered T2 if there was no invasion of adjacent structures)
Example: 7,2 cm necrotic mass
T3: >7cm
Large mass with FDG-avid rim and central photopenia consistent with necrosis
Example: Chest wall invasion
T3: > 7 cm or tumor of any size that directly invades any of the following:
chest wall (including superior sulcus tumors), diaphragm, mediastinal pleura, parietal pericardium; or
tumor in the main bronchus < 2cm distal to the carina, but without involvement of the carina; or
associated atelectasis or obstructive pneumonitis of the entire lung.
Tumors > 7 cm are T3, irrespective of features mentioned above.
TNM Staging 7th Edition: Additional Lung Nodules
 Additional nodules in the same lobe as the
primary tumor are now T3 (previously T4)
 Additional nodules in another ipsilateral lobe are
now T4 (previously M1)
 Contralateral lung nodules are now M1a
(previously M1)
Example: Additional nodules in the same lobe
Additional nodules in the same lobe as the primary tumor are now T3
(previously T4)
TNM Staging System: Regional Lymph Nodes (N)
NX
Regional lymph nodes cannot be assessed
N0
No regional lymph node metastasis
N1
Metastasis to ipsilateral peribronchial and/or ipsilateral hilar lymph nodes,
and intrapulmonary nodes involved by direct extension of the primary
tumor
N2
Metastasis to ipsilateral mediastinal and/or subcarinal lymph node(s)
N3
Metastasis to contralateral mediastinal, contralateral hilar, ipsilateral or
contralateral scalene, or supraclavicular lymph node(s)
No Changes in N Staging!
Example: Ipsilateral hilar lymph nodes
N1: Metastasis to ipsilateral peribronchial and/or ipsilateral hilar lymph nodes,
and intrapulmonary nodes involved by direct extension of the primary tumor
Example: Subcarinal lymphadenopathy
N2: Metastasis to ipsilateral mediastinal and/or subcarinal lymph node(s)
Example: Contralateral hilar nodes
N3: Metastasis to contralateral mediastinal, contralateral hilar, ipsilateral or
contralateral scalene, or supraclavicular lymph node(s)
TNM Staging 7th Edition: Changes in M Staging
MX
Presence of distant metastasis cannot be assessed
M0
No distant metastasis
M1
M1a
M1a
Distant metastasis
present
Contralateral
nodules
(previously M1)
Pleural dissemination (previously T4)
M1b
Distant metastasis
Additional nodules in another ipsilateral lobe are now T4 (previously M1)
Example: Pleural dissemination
Pleural dissemination is now M1a
(previously T4)
Example: Distant metastasis in the adrenal
Distant metastasis is now M1b
(previously M1)
Example: Distant metastases in liver and adrenal
Distant metastasis is now M1b
(previously M1)
Example: Distant metastasis in bone
Distant metastases in the bones are now M1b
(previously M1)
So now that we have gone step by step
through all the changes…
Let’s put it all together in one table!
6th vs. 7th ed: Summary of changes
6th edition T and M
descriptors
7th edition T and M
descriptors
N0
N1
N2
N3
T1 (<=2 cm)
T1a
IA
IIA
IIIA
IIIB
T1 (>2-3 cm)
T1b
IA
IIA
IIIA
IIIB
T2 (<= 5 cm)
T2a
IB
IIA
IIIA
IIIB
T2 (>5-7 cm)
T2b
IIA
IIB
IIIA
IIIB
T2 (>7 cm)
T3
IIB
IIIA
IIIA
IIIB
T3 invasion
T3
IIB
IIIA
IIIA
IIIB
T4 same lobe nodules
T3
IIB
IIIA
IIIA
IIIB
T4 invasion
T4
IIIA
IIIA
IIIB
IIIB
M1 ipsilateral lung
T4
IIIA
IIIA
IIIB
IIIB
T4 pleural effusion
M1a
IV
IV
IV
IV
M1 contralateral lung
M1a
IV
IV
IV
IV
M1 distant
M1b
IV
IV
IV
IV
* Changes to the staging groups are in red
So after all these changes, here’s what
the new TNM staging system looks like:
The New TNM Staging System
Stage Groups
T
N
M
Ia
T1a,b
N0
M0
Ib
T2a
N0
M0
IIa
T1a,b
T2a
T2b
N1
N1
N0
M0
M0
M0
IIb
T2b
T3
N1
N0
M0
M0
IIIa
T1-3
T3
T4
N2
N1
N0,1
M0
M0
M0
IIIb
T4
T1-4
N2
N3
M0
M0
IV
any
any
M1a,b
Conclusions
• Staging is critical to selecting patient appropriately
for surgery and multimodality therapy.
• PET/CT is important in staging patients with lung
cancer and is becoming increasingly popular.
• Our presentation provides practical insights into
the changes to the TNM staging system for lung
cancer.
Thank you …
We hope you enjoy ECR 2010!
References
AJCC Cancer Staging Manual, 7th edition; 2010.
American Cancer Society, Surveillance and Health Policy Research, 2009.
Katz S, Ferrara T, Alavi A,Torigian D. PET, CT, and MR imaging for assessment of thoracic malignancy: structure
meets function. PET Clinics 2009; 3: 395-410.
Kligerman S, Digumarthy S. Staging of non-small cell lung cancer using integrated PET/CT. AJR Am J
Roentgenol 2009;193: 1203-1211.
Patz EF, Jr., Connolly J, Herndon J. Prognostic value of thoracic FDG PET imaging after treatment for non-small
cell lung cancer. AJR Am J Roentgenol 2000; 174(3):769-74.
Gould MK, Maclean CC, Kuschner WG, Rydzak CE, Owens DK. Accuracy of positron emission tomography for
diagnosis of pulmonary nodules and mass lesions: a meta-analysis. Jama 2001; 285(7):914-24.
Demura Y. 18F-FDG accumulation with PET for differentiation between benign and malignant lesions in the
thorax. J Nucl Med. 2003; 44(4):540-8.
Wahl, RL, Buchanan, JW, editors. Principles and Practice of Positron Emission Tomography. Philadelphia:
Lippincott Williams & Wilkins; 2002.