TNM Classification of Lung Cancer
| Classification | Description |
|---|---|
| Primary tumor (T) | |
| TX | Primary tumor cannot be assessed; or tumor proven by presence of malignant cells in sputum or bronchial washes but not visualized by imaging or bronchoscopy |
| T0 | No evidence of primary tumor |
| Tis | Carcinoma in situ |
| T1 | Tumor 3 cm or less in greatest dimension, surrounded by lung or visceral pleura, without bronchoscopic evidence of invasion more proximal than lobar bronchus (i.e., not in main bronchus) |
| T2 | Tumor with any of the following features of size or extent: more than 3 cm in greatest dimension; involves main bronchus, 2 cm or more distal to carina; invades visceral pleura; or associated with atelectasis or obstructive pneumonitis that extends to hilar region but does not involve entire lung |
| T3 | Tumor of any size that directly invades any of following: chest wall (including superior sulcus tumors), diaphragm, mediastinal pleura, or parietal pericardium; tumor in main bronchus less than 2 cm distal to carina but without involvement of carina; or associated atelectasis or obstructive pneumonitis of entire lung |
| T4 | Tumor of any size that invades any of following: mediastinum, heart, great vessels, trachea, esophagus, vertebral body, or carina; or tumor with malignant pleural or pericardial effusion or with satellite tumor nodule(s) within lobe of lung ipsilateral to lobe with primary tumor |
| Regional lymph nodes (N) | |
| NX | Regional lymph nodes cannot be assessed |
| N0 | No regional lymph node metastasis |
| N1 | Metastasis to ipsilateral peribronchial or ipsilateral hilar lymph nodes or both and involvement of intrapulmonary nodes by direct extension of primary tumor |
| N2 | Metastasis to ipsilateral mediastinal or subcarinal lymph nodes |
| N3 | Metastasis to contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene, or supraclavicular lymph nodes |
| Distant metastasis (M) | |
| MX | Presence of distant metastasis cannot be assessed |
| M0 | No distant metastasis |
| M1 | Distant metastasis present |
Reprinted with permission of (51).