A phase II study of combined 5-fluorouracil and mitomycin C in advanced breast cancer.

In a Phase II study, 50 patients with advanced breast cancer were treated with a combination of 5-fluorouracil (1000 mg/m2 on days 1 and 2) and mitomycin C (6 mg/m2 on day 2) (FuMi regimen). The courses were repeated every third to sixth week. Although 35 patients had previously received combination chemotherapy and 40 patients had received endocrine treatment, objective responses were obtained in 29 patients (six complete, 23 partial). The survival was significantly correlated to the response (P less than 0.001, log rank test) complete versus partial response, partial response versus no change, no change versus progressive disease. The regimen was well tolerated (19 of 50 experienced nausea). Thirteen patients had hematopoietic toxicity at the day of starting a new course and in six cases, the FuMi regimen had to be discontinued because of longlasting thrombocytopenia. Otherwise, no side-effect of clinical importance was observed. The FuMi regimen is now compared with Adriamycin regimens and can be recommended for both first line chemotherapy and salvage chemotherapy.