Non-Small Cell Lung Cancer Staging 

Updated: Jan 28, 2018
  • Author: Marvaretta M Stevenson, MD; Chief Editor: Nagla Abdel Karim, MD, PhD  more...
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TNM Classification for Non-Small Cell Lung Cancer

The American Joint Committee on Cancer (AJCC) tumor/node/metastasis (TNM) classification and anatomic stage/prognostic grouping for non–small cell lung cancer are presented below. [1]

See Clinical Presentations of Lung Cancer: Slideshow, a Critical Images slideshow, to help efficiently distinguish lung carcinomas from other lung lesions, as well as how to stage and treat them.

Table 1. TNM Classification for Non-Small Cell Lung Cancer (Open Table in a new window)

Primary tumor (T)
TX Primary tumor cannot be assessed, or tumor is proven by the presence of malignant cells in sputum or bronchial washings but not visualized by imaging or bronchoscopy
T0 No evidence of primary tumor
Tis Carcinoma in situ

Squamous cell carcinoma in situ (SCIS)

Adenocarcinoma in situ (AIS):  adenocarcinoma with pure lepidic pattern, ≤ 3 cm in greatest dimension

T1 Tumor ≤ 3 cm in greatest dimension, surrounded by lung or visceral pleura, without bronchoscopic evidence of invasion more proximal than the lobar bronchus (ie, not in the main bronchus)
T1mi Minimally invasive adenocarcinoma: adenocarcinoma (≤ 3 cm in greatest dimension) with a predominantly lepidic pattern and ≤ 5 mm invasion in greatest dimension
T1a Tumor ≤ 1 cm in greatest dimension.  A superficial, spreading tumor of any size whose invasive component is limited to the bronchial wall and may extend proximal to the main bronchus also is classified as T1a, but those tumors are uncommon. 
T1b Tumor > 1 cm but ≤ 2 cm in greatest dimension
T1c Tumor > 2 cm but ≤ 3 cm in greatest dimension
T2 Tumor > 3 cm but ≤ 5 cm or having any of the following features:

  • Involves the main bronchus regardless of distance to the carina, but without involvement of the carina
  • Invades visceral pleura (PL1 or PL2)
  • Associated with atelectasis or obstructive pneumonitis extending to the hilar region, involving part or all of the lung
T2 tumors with these features are classified as T2a if ≤ 4 cm or if the size cannot be determined and T2b if > 4 cm but ≤ 5 cm

T2a Tumor > 3 cm but ≤ 4 cm in greatest dimension
T2b Tumor > 4 cm but ≤ 5 cm in greatest dimension
T3 Tumor > 5 cm but ≤ 7 cm in greatest dimension or directly invading any of the following:  parietal pleural (PL3), chest wall (including superior sulcus tumors), phrenic nerve, parietal pericardium; or separate tumor nodule(s) in the same lobe as the primary
T4 Tumor > 7 cm or tumor of any size that invades one or more of the following:  diaphragm, mediastinum, heart, reat vessels, trachea, recurrent laryngeal nerve, esophagus, vertebral body, or carina; or separate tumor nodule(s) in an ipsilateral lobe different from that of the primary
Regional lymph nodes (N)
NX Regional lymph nodes cannot be assessed
N0 No regional node metastasis
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 the 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; tumor with pleural or pericardial nodules or malignant pleural or pericardial effusion.  Most pleural (pericardial) effusion with lung cancer are a result of the tumor.  In a few patients, however, multiple miscroscopic examinations of pleural (pericardial) fluid are negative for tumor, and the fluid is nonbloody and not an exudate.  If these elements and clinical judgment dictate that the effusion is not related to the tumor, the effusion should be excluded as a staging descriptor.
M1b Single extrathoracic metastasis in a single organ and involvement of a single nonregional node
M1c Multiple extrathoracic metastases in a single organ or in multiple organs


Table 2. Anatomic stage/prognostic groups. (Open Table in a new window)

Stage T N M
0 Tis N0 M0
IA1 T1mi N0 M0
T1a N0 M0
IA2 T1b N0 M0
IA3 T1c N0 M0
IB T2a N0 M0
IIA T2b N0 M0
IIB T1a N1 M0
T1b N1 M0
T1c N1 M0
T2a N1 M0
T2b N1 M0
T3 N0 M0
IIIA T1a N2 M0
T1b N2 M0
T1c N2 M0
T2a N2 M0
T2b N2 M0
T3 N1 M0
T4 N0 M0
T4 N1 M0
IIIB T1a N3 M0
T1b N3 M0
T1c N3 M0
T2a N3 M0
T2b N3 M0
T3 N2 M0
T4 N2 M0
T4 N3 M0
IVA T Any N Any M1a
  T Any N Any M1b
IVB T Any N Any M1c