The purpose of this randomized trial was to evaluate the efficacy of combination chemoimmunotherapy compared with chemotherapy alone. A total of 124 patients were randomized to receive intravenous cisplatin (35 mg m 72 , days 1 -3), carmustine (150 mg m 72 , day 1, cycles 1 and 3 only), dacarbacine (220 mg m 72 , days 1 -3) and oral tamoxifen (20 mg m 72 , daily) in combination with (n=64) or without (n=60) sequential subcutaneous IL-2 and IFN-a. In those patients who received sequential immunotherapy, each cycle of chemotherapy was followed by outpatient s.c. IL-2 (10610 6 IU m 72 , days 3 -5, week 4; 5610 6 IU m 72 , days 1, 3, 5, week 5) and s.c. IFN-a (5610 6 IU m 72 , day 1, week 4; days 1, 3, 5, week 5). The overall response rate of patients treated with the combination of chemotherapy and IL-2/IFN-a was 34.3% with seven complete responses (10.9%) and 15 partial responses (23.4%). In patients treated with chemotherapy, only, the overall response rate was 29.9% with eight complete responses (13.3%) and 10 partial responses (16.6%). There was no significant difference in median progression free survival (0 months vs 4 months) and in median overall survival (12 months vs 13 months) for combined chemoimmunotherapy and for chemotherapy, respectively.