Background: Postoperative radiotherapy is commonly used to treat patients with completely resected nonsmall cell lung carcinoma, but its effect on overall survival has not been established.
Methods: After undergoing complete surgical resection, 728 patients with non-small cell lung carcinoma (221 Stage I, 180 Stage II, and 327 Stage III) were randomized to receive either postoperative radiotherapy at a total dose of 60 gray or observation only . The main end point was overall survival.
Results: At the reference date, 218 of 355 patients in the control group had died and 262 of 373 in the radiotherapy group had died. Five-year overall survival was 43% for the control group and 30% for the radiotherapy group (P = 0.002, log rank test; relative risk [RR]: 1.33; 95% confidence interval [CI]: 1.11-1.59). This result was not modified by adjustment for potential prognostic factors. The excess mortality rate for the radiotherapy group was due to an excess of intercurrent deaths (P = 0.0001; RR: 3.47; the 5-year intercurrent death rate was 8% for the control group and 31% for the radiotherapy group). Radiotherapy had no significant effect on local recurrence (RR: 0.85; 95% CI: 0.64-1.14) and no effect on metastasis (RR: 1.06; 95% CI: 0.85-1.31). The rate of non-cancer-related death increased with the dose per fraction delivered.