Long-term survival (greater than or equal to 3 years) is possible in a small proportion of patients with SCLC, particularly if the disease is limited in extent. The influence of thoracic irradiation on the long-term outcome of limited stage patients is controversial, although there is a suggestion of benefit. Despite the use of irradiation, thoracic recurrence is the single most important site of treatment failure. Further experience will be necessary to determine if radiotherapeutic strategies to enhance thoracic control can improve long-term survival. Prophylactic cranial irradiation (PCI) may influence long-term survival of limited stage patients who achieve a complete response to therapy and remain controlled in the chest. However, this is not clearly established and must be considered in the light of the contribution of PCI to neurotoxicity occurring in survivors. Reduction in the radiation fraction size and the omission of chemotherapeutic agents which cause neurotoxicity, either alone or by synergism with PCI, are reasonable approaches to pursue in an attempt to prevent this complication. A small proportion of NSCLC occurring after treatment of SCLC may be preventable by attempts to eradicate NSCLC components present in the original SCLC. Leukemogenic chemotherapy agents may contribute to the development of secondary ANL, and should probably not be used in view of the availability of alternative equally effective agents.