Prognostic and predictive factors for lung cancer

T: tumour size (T1: ≤3 cm without bronchoscopic evidence of invasion more than proximal than the lobar bronchus; T1a: T1 ≤2 cm; T1b: T1 >2 cm and ≤ = 3 cm; T2: >3 cm and ≤7 cm or invasion of main bronchus, visceral pleura or associated with atelectasis or obstructive pneumonitis that extends to hilar region without extending to the whole lung; T2a: >3 cm and ≤5 cm; T2b: >5 cm and ≤7 cm; T3: >7 cm or invasion of chest wall, diaphragm, phrenic nerve, mediastinal pleura, parietal pericardum or tumour in the main bronchus without involvement of the carina or associated with atelectasis or obstructive pneumonitis that extends to the whole lung or separate tumour nodule in the same lobe; T4: tumour of any size with invasion of mediastinum or heart or great vessels or trachea or recurrent laryngeal nerve, oesophagus, vertebral body, carina or separate nodule in a different ipsilateral lobe). N: regional lymph node (N0: no regional lymph node metastasis; N1: metastasis in ipsilateral peribronchial and/or ipsilateral hilar lymph nodes and intraplumonary node; N2: metastasis in ipsilateral mediastinal and/or subcarinal lymph node; N3: metastasis in contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene or supraclavicular lymph nodes). M: distant metastasis (M0: no distant metastasis; M1: distant metastasis; M1a: separate nodules in a contralateral lobe, tumour with pleural nodules or malignant pleural or pericardial effusion; M1b: other distant metastasis). cTNM 5Y: rate of survival at 5 years when stage is clinically assessed; pTNM 5Y: rate of survival at 5 years when stage is pathologically assessed; cHR: hazard ratio for comparing overall survival of that clinical stage to the nearest less severe stage (for example cIB versus cIA or cIIIB versus cIIIA); pHR: hazard ratio for comparing overall survival of that pathological stage to the nearest less severe stage.