Results of pneumonectomy for non-small cell lung cancer: appropriateness of the new TNM staging system.

In the new TNM staging system for lung cancer in 1997, stage T3N0M0 was revised from stage IIIA to stage IIB. Therefore, we initiated a study to assess the appropriateness of this revision. One hundred and nineteen patients who had undergone pneumonectomy for non-small cell lung cancer (NSCLC) between January 1985 and March 1996 were analyzed. They included 87 squamous cell carcinoma (sq), 25 adenocarcinoma (ad), 4 large cell carcinoma (la), and 3 adenosquamous cell carcinoma (ad-sq), with 10 patients in postoperative stage I (3 IA + 7 IB), 29 stage II (1 IIA + 28 IIB), 74 stage III (39 IIIA + 35 IIIB) and 6 in stage IV of the disease. Stage IIB included 14 patients with T3N0M0 (12 sq, 1 ad, 1 la). The 5-year survival rate for patients with T3N0M0 was 69.6%, which was superior to that (55.7%) for patients with stage II (T1-2N1M0) of the previous system. According to the new TNM staging system, the 5-year survival rate was 40% in stage I, 66.2% in stage II, 24% in stage IIIA, 0% in stages IIIB and IV (stage I vs stage II, NS; stage II vs stage IIIA, p<0.01; stage IIIA vs stage IIIB, p<0.01; stage IIIB vs stage IV, p<0.01). A significant prognostic difference between stage II and stage IIIA was observed, which had not been observed in the previous system. Our results show that the revision of T3N0M0 from stage IIIA to stage II in the new TNM staging system seems appropriate with regard to the pneumonectomy group.