Stage		Description
Non–small cell carcinoma (TNM staging system)
Local
	IA (T1N0M0)	T1: 3 cm or less in diameter; surrounded by lung or pleura; does not invade main bronchus
	IB (T2N0M0)	T2: more than 3 cm in diameter; may invade pleura; may extend into main bronchus but remains 2 cm or more distal to carina; may cause segmental atelectasis or pneumonitis
	IIA (T1N1M0)	N1: involvement of ipsilateral peribronchial or hilar nodes and intrapulmonary nodes
Locally advanced
	IIB (T2N1M0 and T3N0M0)	T3: invasion of chest wall, diaphragm, pleura, or pericardium; main bronchus less than 2 cm distal to carina; atelectasis of entire lung
	IIIA (T1N2M0, T2N2M0, T3N1M0, and T3N2M0)	N2: involvement of ipsilateral mediastinal or subcarinal nodes
	IIIB (T1-4N3M0)	N3: involvement of contralateral nodes or any supraclavicular nodes
Advanced
	IIIB (T4N1-3M0)	T4: invasion of mediastinum, heart, great vessels, trachea, esophagus, vertebral body, or carina; separate tumor nodules; malignant pleural effusion
	IV (T1-4N1-3M1)	Distant metastasis
Small cell carcinoma
Limited		Disease confined to the ipsilateral hemithorax
Extensive		Disease with metastasis beyond the ipsilateral hemithorax