NEW STAGING SYSTEM FOR LUNG CANCER

Changes in the proposed seventh edition of TNM classification of lung tumors

Primary tumor (T):

T1 lesions are divided based upon size into T1a (2 cm) and T1b (>2 cm but 3 cm)

T2 lesions are divided into T2a (>3 cm but 5 cm) and T2b (>5 cm but 7 cm)

T2 tumors >7 cm are reclassified as T3

T4 tumors with satellite nodules in the same lobe as the primary tumor are reclassified as T3

Additional nodules in a different lobe of same lung are reclassified as T4 rather than M1

Malignant pleural or pericardial effusions or pleural nodules are now classified as metastasis (M1a) rather than T4

Regional nodes (N):

No changes

Metastasis (M):

Subdivided into M1a (malignant pleural or pericardial effusion, pleural nodules, nodules in contralateral lung) and M1b (distant metastasis)

Stage grouping:

T2aN1M0 lesions are classified as IIA, rather than IIB

T2bN0M0 lesions are classified as IIA, rather than IB

T3 (>7 cm), N0M0 lesions are classified as IIB, rather than IB

T3 (>7 cm), N1M0 lesions are classified as IIIA, rather than IIB

T3N0M0 (nodules in same lobe) lesions are classified as IIB, rather than IIIB

T3N1M0 or T3N2M0 (nodules in same lobe) are classified as IIIA, rather than IIIB

T4M0 (ipsilateral lung nodules) lesions are classified as IIIA (if N0 or N1) and IIIB (if N2 or N3), rather than stage IV

T4M0 (direct extension) lesions are classified as IIIA (if N0 or N1), rather than IIIB

Malignant pleural effusions (M1a) are classified as IV, rather than IIIB

Proposed 7th edition TNM staging system for lung cancer Primary tumor (T)
T1 - Tumor 3 cm diameter, surrounded by lung or visceral pleura, without invasion more proximal than lobar bronchus
T1a - Tumor 2 cm in diameter
T1b - Tumor >2 cm but 3 cm in diameter
T2 - Tumor >3 cm but 7 cm, or tumor with any of the following features:
Involves main bronchus, 2 cm distal to carina
Invades visceral pleura
Associated with atelectasis or obstructive pneumonitis that extends to the hilar region but does not involve the entire lung
T2a - Tumor >3 cm but 5 cm
T2b - Tumor >5 cm but 7 cm
T3 - Tumor >7 cm or any of the following:
Directly invades any of the following: chest wall, diaphragm, phrenic nerve, mediastinal pleura, parietal pericardium, main bronchus <2>
Atelectasis or obstructive pneumonitis of the entire lung
Separate tumor nodules in the same lobe
T4 - Tumor of any size that invades the mediastinum, heart, great vessels, trachea, recurrent laryngeal nerve, esophagus, vertebral body, carina, or with separate tumor nodules in a different ipsilateral lobe
Regional lymph nodes (N)
N0 - No regional lymph node metastases
N1 - Metastasis in ipsilateral peribronchial and/or ipsilateral hilar lymph nodes and intrapulmonary nodes, including involvement by direct extension
N2 - Metastasis in ipsilateral mediastinal and/or subcarinal lymph node(s)
N3 - Metastasis in contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene, or supraclavicular lymph node(s).
Distant metastasis (M)
M0 - No distant metastasis
M1 - Distant metastasis
M1a - Separate tumor nodule(s) in a contralateral lobe; tumor with pleural nodules or malignant pleural or pericardial effusion
M1b - Distant metastasis
Stage groupings
Stage IA:	T1a-T1b	N0	M0
Stage IB:	T2a	N0	M0
Stage IIA:	T1a-T2a	N1	M0
	T2b	N0	M0
Stage IIB:	T2b	N1	M0
	T3	N0	M0
Stage IIIA:	T1a-T3	N2	M0
	T3	N1	M0
	T4	N0-N1	M0
Stage IIIB:	T4	N2	M0
	T1a-T4	N3	M0
Stage IV:	Any T	Any N	M1a or M1b