To assess the results of therapeutic advances in the treatment of small cell carcinoma of the lung (SCCL) achieved during the past 15-year period at a single large institution, 508 patients treated between 1968 and 1982 were divided into two groups: 157 patients (66 in the category of limited-stage disease and 91 in the extensive-stage disease category) treated with low-dose small-volume radiotherapy (RT) (time dose fractionation [TDF] 49-66) and with cyclophosphamide alone or a COPP program during the first period of 7 years (1968-1974); 351 patients (180 in limited and 171 in extensive stage) treated with multidrug chemotherapy (CT) and high-dose large-volume RT (TDF 73-89) during the second period of 8 years (1975-1982). For patients with limited-stage cancer, 5-year actuarial survivals were 3% versus 7% for the periods 1968-1974 versus 1975-1982, respectively, P less than 0.01. For patients with extensive-stage cancer, the median survival time (MST) and 2-year actuarial survivals were 5 months and 2% versus 7 months and 4% for the periods 1968-1974 versus 1975-1982, respectively. To evaluate the outcome of a contemporary approach, i.e., CT alone, with RT reserved for locoregional failure, 180 patients with limited-stage cancer who were treated (1975-1982) were further analyzed for MST, 2- and 5-year actuarial survival figures, and local-tumor control rates according to the therapeutic approaches employed: CT + RT (112); CT alone (36); RT alone (17); and surgery (S) +/- CT +/- RT (15). Although the 36 patients in CT alone seems a small number, 17 of the 36 patients were enrolled in this approach in 1981-1982, reflecting a shift of emphasis from RT to CT. The MST and 2-year actuarial survival figures were 11 months and 0% versus 13 months and 21% for CT alone versus CT + RT respectively, P less than 0.05. CT + RT achieved a 5-year cure rate of 8%. S +/- CT +/- RT or RT alone also achieved 5-year cure rates of 8% and 10.5%, respectively, in selected subsets of patients. Local relapse rates were 80% (29/36) versus 25% (28/112) for CT alone versus CT + RT. These data emphasize the importance of thoracic RT given at the early phase of treatment to improve long-term survival for patients with limited-stage SCCL.