STAGE GROUPING OF THE TNM SUBSETS (continued)

Stage IIIB designates patients with extensive primary tumor invasion of the mediastinum and metastases to the contralateral mediastinal, contralateral hilar, and ipsilateral and contralateral scalene/supraclavicular lymph nodes. Patients with a T4 primary tumor classification or N3 regional lymph node metastasis, but no distant metastasis, are included.

Stage IV is reserved for patients with evidence of distant metastatic disease, M1, such as metastases to brain, bone, liver, adrenal gland, contralateral lung, pancreas and other distant organs, and metastases to distant lymph node groups such as axillary, abdominal, inguinal, etc. Patients with metastasis in ipsilateral nonprimary tumor lobes of the lung are also designated M1.

TNM Subsets by Stage

Stage 0	Carcinoma in situ
Stage IA	T1 - N0 - M0
Stage IB	T2 - N0 - M0
Stage IIA	T1 - N1 - M0
Stage IIB	T2 - N1 - M0
	T3 - N0 - M0
Stage IIIA	T3 - N1 - M0
	T1 - N2 - M0	T2 - N2 - M0	T3 - N2 - M0
Stage IIIB	T4 - N0 - M0	T4 - N1 - M0	T4 - N2 - M0
	T1 - N3 - M0	T2 - N3 - M0	T3 - N3 - M0
	T4 - N3 - M0
Stage IV	Any T	Any N	M1