The proportion of small cell-large cell or combined small-cell subtypes is very low, and the clinical outcome in patients with these subtypes appears not to be significantly different from that of the majority of patients with small-cell lung cancer. Anatomic staging of small-cell lung cancer remains necessary if the outcome influences treatment decisions and for treatment in many clinical trials. The influence of simple clinical and biochemical variables on prognosis has been confirmed by the analysis of very large numbers of patients. Patients with small-cell lung cancer surviving at 2 years after chemotherapy continue to be at risk for relapse for up to 5 more years independent of the initial stage of disease. Major future directions will include the investigation into possible correlations of biologic properties of tumors with prognosis and the use of simple clinical and biochemical parameters to preselect patients for treatment strategies according to risk groups.