Stage III includes: IIIA (T1a, N2, M0); (T1b, N2, M0); (T2a, N2, M0); (T2b, N2, M0); (T3, N1, M0); (T3, N2, M0); (T4, N0, M0); (T4, N1, M0) and IIIB (T1a, N3, M0); (T1b, N3, M0); (T2a, N3, M0); (T2b, N3, M0); (T3, N3, M0); (T4, N2, M0); (T4, N3, M0). T4: Lung cancer with a tumor of any size that invades any of the following: mediastinum, heart, great vessels, trachea, recurrent laryngeal nerve, esophagus, vertebral body, carina, and separate tumor nodule(s) in a different ipsilateral lobe. N1: Lung cancer with metastasis in ipsilateral peribronchial and/or ipsilateral hilar lymph nodes and intrapulmonary lymph nodes, including involvement by direct extension. N2: Lung cancer with metastasis to ipsilateral mediastinal and/or subcarinal lymph nodes. N3: Lung cancer with metastasis to contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene, or supraclavicular lymph nodes. M0: No distant metastasis. (AJCC 7th ed.) [from NCI]