Primary tumor.
T0 without primary tumor.
T1 ≤ 3 cm, surrounded by lung or visceral pleura, without involvement of lobar bronchi above the proximal position.
T1a≤2cm.
T1b>2cm but ≤3cm.
T2>3cm but ≤7cm or tumor with any of the following: invasion of the dirty pleura, involvement of the main bronchus, ≥2cm from the bullae, and spread of pulmonary atelectasis/obstructive pneumonia to the hilum but without involvement of the whole lung.
T2a>3cm but ≤5cm.
T2b>5cm but ≤7cm.
T3>7cm, or direct invasion of the chest wall/diaphragm/phrenic nerve/mediastinal pleura/mural pericardium, or tumor located in the main bronchus, <2cm ≤2cm from the bullae, or total pulmonary atelectasis/obstructive pneumonia, or separate tumor nodules located in the same lung lobe.
T4 tumor of any size invading to the heart/large blood vessels/trachea/recurrent laryngeal nerve/esophagus/vertebral body or bullae, or separate tumor nodes located in different lung lobes ipsilaterally.
Lymph nodes.
N0 no regional lymph node metastasis.
N1 metastasis to ipsilateral peribronchial and/or periportal lymph nodes and intrapulmonary lymph nodes, including direct spread involvement.
N2 metastasis to the ipsilateral mediastinum and/or subsurface lymph nodes of the bulge.
N3 metastasis to contralateral mediastinal lymph nodes, contralateral hilar lymph nodes, ipsilateral or contralateral oblique muscle lymph nodes, and supraclavicular lymph nodes.
Distant metastases.
M0 no distant metastasis.
M1a separate tumor nodes located in one contralateral lobe, or tumor with pleural nodes or malignant pleural dissemination.
M1b distant metastasis.
TNM staging.