Table 1.
Lung cancer TNM staging system (adapted from ref.[6])
| Primary tumor (T) | |||
| TX | Primary tumor cannot be assessed, or tumor 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, without bronchoscopic evidence of invasion more proximal than the lobar bronchus (for example, not in the main bronchus) | ||
| T1a | Tumor ≤ 2 cm in greatest dimension | ||
| T1b | Tumor > 2 cm but ≤ 3 cm in greatest dimension | ||
| T2 | Tumor > 3 cm but ≤ 7 cm or tumor with any of the following features (T2 tumors with these features are classified T2a if ≤ 5 cm): involves main bronchus, 2 cm or more distal to the carina; invades visceral pleura (PL1 or PL2); 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 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: parietal pleural (PL3), chest wall (including superior sulcus tumors), diaphragm, phrenic nerve, mediastinal pleura, parietal pericardium; or tumor in the main bronchus < 2 cm distal to the carina but without involvement of the carina; or associated atelectasis or 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: mediastinum, heart, great vessels, trachea, recurrent laryngeal nerve, esophagus, vertebral body, carina, 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 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 (in extrathoracic organs) | ||
| T | N | M | |
| Anatomic stage | |||
| Occult carcinoma | TX | N0 | M0 |
| Stage 0 | Tis | N0 | M0 |
| Stage IA | T1a | N0 | M0 |
| T1b | N0 | M0 | |
| Stage IB | T2a | N0 | M0 |
| Stage IIA | T2b | N0 | M0 |
| T1a | N1 | M0 | |
| T1b | N1 | M0 | |
| T2a | N1 | M0 | |
| Stage IIB | T2b | N1 | M0 |
| T3 | N0 | M0 | |
| Stage IIIA | T1a | N2 | M0 |
| T1b | N2 | M0 | |
| T2a | N2 | M0 | |
| T2b | N2 | M0 | |
| T3 | N1 | M0 | |
| T3 | N2 | M0 | |
| T4 | N0 | M0 | |
| T4 | N1 | M0 | |
| Stage IIIB | T1a | N3 | M0 |
| T1b | N3 | M0 | |
| T2a | N3 | M0 | |
| T2b | N3 | M0 | |
| T3 | N3 | M0 | |
| T4 | N2 | M0 | |
| T4 | N3 | M0 | |
| Stage IV | Any T | Any N | M1a |
| Any T | Any N | M1b | |