Post-operative radiotherapy (PORT) or chemoradiotherapy (CPORT) following resection of stages II and IIIA non-small cell lung cancer (NSCLC) does not increase the expected risk of death from intercurrent disease (DID) in Eastern Cooperative Oncology Group (ECOG) trial E3590.

To determine the influence of adjuvant therapy on the risk of DID following resection of NSCLC, we compared the actuarial rate of non-cancer related deaths of patients who had been entered in Eastern Cooperative Oncology Group E3590 (a phase III trial of adjuvant therapy in patients with completely resected stages II and IIIA NSCLC) to the actuarial death rate of age and gender matched controls. Following surgery, patients were randomized to receive either PORT (5040 cGy in 28 daily fractions) or CPORT (PORT plus four cycles of cisplatin (60 mg/m2, day 1) and etoposide (120 mg/m2, days 1-3) administered concurrently). The study accrued 488 patients, 242 to the PORT only arm and 246 to the CPORT arm. The overall 4 years actuarial rate of DID for the two arms combined, with a median follow-up of 82 months, was 12.9%, not significantly different from the 10.1% expected rate of DID, based on mortality rates for age and gender matched controls derived from US vital statistics and corrected for smoking status (p=0.16). Survival distributions with regard to DID did not differ between the two treatment arms (p=0.96). DID increased with age (treated as a continuous variable, p<0.01), but was not affected by histology, side of chest irradiated, type of surgery, FEV1 or weight loss in the previous 6 months. The risk of DID following resection of stages II and IIIA NSCLC is not increased in patients who received PORT or CPORT.