Mortality and morbidity in long-term surviving patients treated with chemotherapy with or without irradiation for small-cell lung cancer.

Mortality and morbidity was investigated in a consecutive series of 72 patients with small-cell lung cancer (SCLC) who were found to be disease-free at restaging after 18 months of treatment. These patients were all the long-term survivors among 874 patients included in one of six trials between 1973 and 1981. All studies used combination chemotherapy with or without irradiation. Follow-up of the patients varied between 4 and 11 years. The estimated 5-year survival rate subsequent to discontinuation of therapy was 0.24, corresponding to a death rate of 0.25 per year or ten times greater than the expected mortality for persons of the same age group. This high mortality was primarily related to recurrent SCLC, the estimated cumulative risk of relapse reaching 46% at the time of the latest recurrence 5 years from diagnosis. The risk of relapse was generally independent of the pretreatment disease stage although it was reduced in patients with resectable disease and was greater in those with pretreatment liver or bone marrow metastases. Equal risks of relapse were related to the use of regimens with and without radiotherapy. The cumulative risk of relapse in patients surviving 3 years from initiation of the treatment was less than 15% and accordingly, 3 years of follow-up seems sufficient for comparison of long-term results obtained in different trials. The second factor resulting in death or disease was second cancer, for which the cumulated risk increased to 32%, the latest occurring 5.4 years from the diagnosis of SCLC. Five of these cases were non-small-cell lung cancers and three were secondary leukemias. The estimated mortality related to non-neoplastic conditions was just significantly greater than expected. In spite of the increased mortality in this series, 38 of 54 2-year disease-free survivors and 20 of 22 5-year survivors resumed a lifestyle similar to that before diagnosis of SCLC.