Stage III non-small cell lung cancer is divided into stages IIIA and IIIB. In stage IIIB, cancer has spread to lymph nodes above the collarbone or in the opposite side of the chest as the tumor. Also, (1) the tumor may be any size; (2) part of the lung (where the trachea joins the bronchus) or the whole lung may have collapsed or become inflamed; (3) there may be one or more separate tumors in any of the lobes of the lung with cancer; and/or (4) cancer may have spread to any of the following: main bronchus, diaphragm and the nerve that controls it, membrane around the lung, chest wall or the membrane that lines it, trachea, carina (where the trachea joins the bronchi), esophagus, sternum (chest bone), backbone, heart or the membrane around it, major blood vessels that lead to or from the heart, or the nerve that controls the larynx (voice box). OR in stage IIIB, cancer has spread to lymph nodes on the same side of the chest as the tumor. Also, (1) the tumor may be any size; (2) there may be separate tumors in different lobes of the same lung; and/or (3) cancer has spread to any of the following: trachea, carina, esophagus, sternum, backbone, major blood vessels that lead to or from the heart, or the nerve that controls the larynx.