STAGE GROUPING OF THE TNM SUBSETS

The TNM subsets are combined in seven stage groups, in addition to stage 0, that reflect fairly precise levels of disease progression and their implications for treatment selection and prognosis. Staging is not relevant for occult carcinoma, TX N0 M0.

Stage 0 is assigned to patients with carcinoma in situ, which is consistent with the staging of all other sites.

Stage IA includes only patients with tumors 3 cm. or less in greatest dimension and no evidence of metastasis, the anatomic subset T1 N0 M0.

Stage IB includes only patients with a T2 primary tumor classification and no evidence of metastasis, the anatomic subset T2 N0 M0.

Stage IIA is reserved for patients with a T1 primary tumor classification and metastasis limited to the intrapulmonary, including hilar, lymph nodes, the anatomic subset T1 N1 M0.

Stage IIB includes two anatomic subsets: patients with a T2 primary tumor classification and metastasis limited to the ipsilateral intrapulmonary, including hilar, lymph nodes, the anatomic subset T2 N1 M0; and patients with a primary tumor classification of T3 and no evidence of metastasis, the anatomic subset T3 N0 M0.

Stage IIIA includes four anatomic subsets that reflect the implications of ipsilateral, limited, extrapulmonary extension of the lung cancer. Patients included are those with a T3 primary tumor classification and metastasis limited to the ipsilateral intrapulmonary, including hilar, lymph nodes, T3 N1 M0 disease, and patients with T1, T2, or T3 primary tumor classifications and metastasis limited to the ipsilateral mediastinal and subcarinal lymph nodes--the T1 N2 M0, T2 N2 M0 and T3 N2 M0 subsets.