TNM classification
| Primary tumour (T) | |
| Tx | Primary tumour cannot be assessed or tumour proven by the presence of malignant cells in sputum or bronchial washings but not visualised by imaging or bronchoscopy |
| T0 | No evidence of primary tumour |
| Tis | Carcinoma in situ |
| T1 | Tumour <3 cm in greatest dimension, surrounded by lung or visceral pleura, without bronchoscopic evidence of invasion more proximal than the lobar bronchus |
| T2 | Tumour with any of the following features of size or extent: |
| • >3 cm in greatest dimension | |
| • involves main bronchus >2 cm distal to the carina | |
| • invades the visceral pleura | |
| • associated with atelectasis or obstructive pneumonitis that extends to the hilar region but does not involve the entire lung | |
| T3 | Tumour of any size that directly invades the following: chest wall (including superior sulcus tumours), diaphragm, mediastinal pleura, parietal pericardium; or tumour 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 |
| T4 | Tumour of any size that involves any of the following: mediastinum, heart, great vessels, trachea, oesophagus, vertebral body, carina; or tumour with a malignant pleural or pericardial effusion, or with satellite tumour nodule(s) within the ipsilateral primary tumour lobe of the lung |
| Regional lymph nodes (N) | |
| Nx | Regional lymph nodes cannot be assessed |
| N0 | No regional lymph node metastases |
| N1 | Metastases to ipsilateral peribronchial and/or ipsilateral hilar lymph nodes and intrapulmonary nodes involved by direct extension of primary tumour |
| N2 | Metastases to ipsilateral mediastinal and/or subcarinal lymph nodes |
| N3 | Metastases to contralateral mediastinal, contralateral hilar, ipsilateral or contralateral saclene or supraclavicular lymph nodes |
| Distant metastases (M) | |
| Mx | Presence of distant metastases cannot be assessed |
| M0 | No distant metastases |
| M1 | Distant metastases present |
| Stage grouping TNM subsets | |
| 0 | Carcinoma in situ |
| IA | T1N0M0 |
| IB | T2N0M0 |
| IIA | T1N1M0 |
| IIB | T2N1M0 |
| T3N0M0 | |
| IIIA | T3N1M0 |
| T1N2M0 | |
| T2N2M0 | |
| T3N2M0 | |
| IIIB | T4N0M0 |
| T4N1M0 | |
| T4N2M0 | |
| T1N3M0 | |
| T2N3M0 | |
| T3N3M0 | |
| T4N3M0 | |
| IV | Any T Any N M1 |