Small Cell Lung Cancer Staging 

Updated: Nov 30, 2015
  • Author: Marvaretta M Stevenson, MD; Chief Editor: Jules E Harris, MD, FACP, FRCPC  more...
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TNM Classification for Small Cell Lung Cancer

The TNM classification for small cell lung cancer is provided below. [1]

See Small Cell Lung Cancer: Beating the Spread, a Critical Images slideshow, to help identify the key clinical and biologic characteristics of small cell lung cancer, the staging criteria, and the common sites of spread.

Also, see Clinical Presentations of Lung Cancer: Slideshow to help efficiently distinguish lung carcinomas from other lung lesions, as well as how to stage and treat them.

Table. TNM Classification for 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
T1 Tumor ≤ 3 cm in greatest dimension, surrounded by lung or visceral pleura, no bronchoscopic evidence of invasion, more proximal than the lobar bronchus (ie, not in the main bronchus); or superficial spreading of tumor in the central airways (confined to the bronchial wall)
T1a Tumor ≤ 2 cm in greatest dimension
T1b Tumor > 2 cm but ≤ 3 cm in greatest dimension
T2 Tumor with any of the following features of size or extent:
  • Tumor > 3 cm but ≤ 7 cm
  • Invades visceral pleura (PL1 or PL2)
  • Involves the main bronchus ≥ 2 cm distal to the carina
  • Associated with atelectasis/obstructive pneumonitis extending to hilar region but not involving the entire lung
T2a Tumor > 3 cm but ≤ 5 cm in greatest dimension
T2b Tumor > 5 cm but ≤ 7 cm in greatest dimension
T3 Tumor > 7 cm, or one that directly invades any of the following:

  • Chest wall (including superior sulcus tumors), parietal pleural (PL3), diaphragm, phrenic nerve, mediastinal pleura, or parietal pericardium;
Or, tumor in the main bronchus < 2 cm distal to the carina but without involvement of the carina; or associated atelectasis/obstructive pneumonitis of the entire lung; or separate tumor nodule(s) in the same lobe

T4 Tumor of any size that invades any of the following: heart, mediastinum, great vessels, trachea, recurrent laryngeal nerve, esophagus, vertebral body, or carina; or separate tumor nodule(s) in a different ipsilateral lobe
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, 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

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

Stage T N M
Limited disease
0 Tis N0 M0
Ia T1a N0 M0
T1b N0 M0
Ib T2a N0 M0
IIa T1a N1 M0
T1b N1 M0
T2a N1 M0
T2b N0 M0
IIb T2b N1 M0
T3 N0 M0
IIIa T1 N2 M0
T2 N2 M0
T3 N1 M0
T3 N2 M0
T4 N0 M0
T4 N1 M0
IIIb T4 N2 M0
T1 N3 M0
T2 N3 M0
T3 N3 M0
T4 N3 M0
Extensive disease IV T Any N Any M1a or 1b
  • Limited disease: Confined to the ipsilateral hemithorax, which can be safely encompassed within a tolerable radiation field (T any, N any, M0; except T3-T4 due to multiple lung nodules that do not fit in a tolerable radiation field)
  • Extensive disease: Beyond ipsilateral hemithorax, which may include malignant pleural or pericardial effusion or hematogenous metastases (T any, N any, M1a/b; T3-T4 due to multiple lung nodules that do not fit in a tolerable radiation field)