Survival after resection for primary lung cancer: a population based study of 3211 resected patients

Very few population based results have been presented for survival after resection for lung cancer. The purpose of this study was to present long term survival after resection and to quantify prognostic factors for survival.

All lung cancer patients diagnosed in Norway in 1993-2002 were reported to the Cancer Registry of Norway (n = 19 582). A total of 3211 patients underwent surgical resection and were included for analysis. Supplementary information from hospitals (including co-morbidity data) was collected for patients diagnosed in 1993-8. Five year observed and relative survival was analysed for patients diagnosed and operated in 1993-9. Factors believed to influence survival were analysed by a Cox proportional hazard regression model.

Five year relative survival in the period 1993-9 was 46.4% (n = 2144): 58.4% for stage I disease (n = 1375), 28.4% for stage II (n = 532), 15.1% for IIIa (n = 133), 24.1% for IIIb (n = 63), and 21.1% for stage IV disease (n = 41). The high survival in stage IIIb and IV was due to the contribution of multiple tumours. Cox regression analysis identified male sex, higher age, procedures other than upper and middle lobectomy, histologies such as adenocarcinoma and large cell carcinoma, surgery on the right side, infiltration of resection margins, and larger tumour size as non-favourable prognostic factors.

Survival was favourable for resected patients in a population based group including subgroups such as elderly patients, those with advanced stage, small cell lung cancer, tumours with nodal invasion, and patients with multiple tumours. These results question the validity of the current TNM system for lung cancer with regard to tumour size and categorization of multiple tumours.