Factors influencing ten-year survival in resected stages I to IIIa non-small cell lung cancer.
OBJECTIVE: The purpose of this study was to determine (in survivors of 5 years after resection of their lung cancer) whether age, sex, histologic condition, and age have any influence on furthering survival beyond 5 years. METHODS: From 1973 to 1989, 686 patients were alive and well 5 years after complete resection of their lung cancers. Survival analysis was carried out with only deaths from lung cancer treated as deaths. Deaths from other causes were treated as withdrawals. Multivariate Cox regression was used to test the relationship of survival to age, sex, histologic condition, and stage. RESULTS: The population in this study had the following characteristics at the time of operation: The male/female ratio was 1.38:1, and the median age was 61 years. The histologic condition of their lung cancer was adenocarcinoma in 412 patients, squamous cell in 244 patients, large cell carcinoma in 29 patients, and small cell carcinoma in 1 patient. The stage of the disease was stage IA in 263 patients, IB in 261 patients, IIA in 12 patients, IIB in 68 patients, and IIIA in 82 patients. The extent of resection was a lobectomy or bilobectomy in 579 patients, pneumonectomy in 55 patients, and wedge resection or segmentectomy in 52 patients. A recurrence or a new lung primary occurrence was considered as failure to remain free of lung cancer. The median follow-up on all patients was 122 months from initial treatment. Of the 686 patients, 26 patients experienced the development of late recurrence and 36 new cancers, beyond 5 years. Overall survival for 5 additional years after a 5-year check point was 92.4%. Likewise, survival by nodal status was 93% for N0 tumors, 95% for N1 tumors, and 90% for N2 tumors. Survival by stage was 93% for stage I tumors and 91% for stage II or IIIA tumors. CONCLUSIONS: In patients with surgically treated lung cancer, neither age, sex, histologic condition, nor stage is a predictor of the risk of late recurrence or new lung cancer. The only prognostic factor appears to be the survival of the patient free of lung cancer for 5 years from the initial treatment, with a resultant favorable outlook to remain well for 10 or more years.