Surgery for non-small cell lung cancer: postoperative survival based on the revised tumor-node-metastasis classification and its time trend.

Objective: To clarify results of surgery for non-small cell lung cancer (NSCLC) based on the new tumor-node-metastasis (TNM) classification revised in 1997 and its time trend.
Methods: A total of 921 patients operated from 1980-1994 were retrospectively reviewed. For analysis of time trend, they were grouped into three periods by the year of operation (period (1): 1980-1984, period (2): 1985-1989, and period (3): 1990-19-94).
Results: Concerning patients' characteristics, recent increase in the ratio of patients whose tumor was discovered at mass screening (31% in period (1), 40% in period (2), and 50% in period (3)), and increase in the ratio of p-stage IA patient (16, 20, and 29%, respectively) were marked. Decrease in the ratio of operation-related death and the ratio of exploratory thoracotomy was significant. Concerning level of operation, decrease in the ratio of pneumonectomy, increase in the ration of sublober resection and that of tracheal or bronchoplastic procedures were significant. Postoperative survival for all patients was significantly better in period (2) or (3) than that in period (1); no significant difference was demonstrated between period (2) and (3) (5-year survival rates: 35% for period (1), 56% for period (2), and 56% for period (3)). Stratified p-stage, improvement of postoperative survival in recent years was demonstrated in p-stage IIA, IIB, IIIA, and IIIB diseases.
Conclusions: Postoperative survival for all NSCLC patients has been improved with significant increase of early-stage (p-stage IA) patients. Concerning level of resection, recent increase in patients who underwent sublobar resection and bronchoplastic procedures was marked.