Impact of tumor extent and location on treatment outcome in patients with stage III non-small cell lung cancer treated with radiation therapy.

The results of treatment of 141 patients with stage III non-small cell lung cancer (NSCLC) who received definitive radiation therapy at Gunma University Hospital between 1976 and 1989 were retrospectively analyzed. Radiation was given with standard fractionation for a planned prophylactic dose of 40 Gy over 4 weeks and a definitive dose of 60 Gy over 6 weeks or more. The two- and five-year survival rates were 27% and 12% for stage IIIA, and 18% and 8% for stage IIIB, respectively (P = 0.052). By univariate analysis, a primary tumor less than 5 cm in diameter was also an important predictor of survival (P = 0.008). As for tumor location, the patients with primary tumors in the upper lobes or the superior segment of the lower lobes of the lung lived longer than those with primary tumors at any other site (P = 0.032). Patients with epidermoid carcinoma had a higher survival rate at 5 years than those with other histologic types (14% vs 3%, P = 0.074). Multivariate analysis showed that among tumor characteristics, the site of the primary tumor, the pattern of tumor spread and N stage were significantly associated with overall survival. Among the patients with stage III NSCLC, those with stage IIIA epidermoid carcinoma in the upper lobe or the superior segment of the lower lobe of the lung were considered to be the most favorable candidates for definitive radiation therapy.