Treatment of patients with small-cell lung cancer (SCLC) remains disappointing despite high initial complete response rates. The dramatic initial chemosensitivity of tumor cells is frustrated by the early emergence of chemoresistant clonogenic cells, regardless of front line treatments. Although the dose relationship is fairly well established regarding the response rate, its effect on survival is inconclusive. From 1980 to 1988, 202 patients with limited SCLC were included in four consecutive protocols using an alternating schedule of thoracic radiotherapy and chemotherapy. Despite an increase of chemotherapy and/or total radiation doses, no significant difference was observed between the four protocols in terms of response rate, disease free and overall survival. However, a retrospective analysis performed on a total of 131 consecutive patients led us to propose the hypothesis that a moderate increase in the initial dose, ie first course, of cisplatin and cyclophosphamide could improve overall survival. From 1988 to 1991, 105 patients were subsequently included in a large randomized trial raising this question. The treatment difference only concerned the initial doses of cisplatin (80 vs 100 mg/m2) and cyclophosphamide (900 vs 1200 mg/m2). The trial was closed after inclusion of 105 patients, 32 months after the start of the study because at that time overall survival was significantly better in the higher-dose group (p = 0.001). The emergence of this debatable concept opens new directions in the therapeutic strategy of SCLC and the contribution of hematopoietic growth factors may be of great interest in the management of this disease.