This study was aimed to evaluate the effect of ifosfamide, cisplatin and etoposide (ICE) combined chemotherapy in small cell lung cancer (SCLC), and to test the feasibility of adding recombinant human granulocyte colony-stimulating factor (rhG-CSF) to aggressive chemotherapy. Thirty consecutive, previously untreated, patients with SCLC (17 with limited disease and 13 with extensive disease) entered this study. The ICE regimen consisted of ifosfamide (I) 4 g/m(2) i.v. with same dose mesna i.v. on first day, cisplatin (C) 25 mg/m(2) i.v. on days 1 to 3 and etoposide (E) 100 mg/m(2) i.v. on days 1 to 3. A total of 30 MU rhG-CSF i.v. were given from day 7 to 14 if WBC were lower than 3000x10(6)/L, neutrophils were lower than 1000x10(6)/L. Overall response (OR) rate was 93% with a complete response (CR) rate of 23%. Median survival was 12 months [95% confidence interval (CI): 11-14] and median response duration was 10 months [95% CI: 8-10]. Thirty-seven percent of: patients had grade 3 neutropenia, 40% had grade 3 anemia, and 1% had grade 2 thrombocytopenia. Nonhematologic toxicity was mild with nausea and vomiting being the most common. RhG-CSF, which reduced leukopenic nadirs and shortened the neutropenic period, was also well tolerated. This chemotherapy protocol seems to be active, well tolerated and is currently being compared with various conventional chemotherapies.