Phase II trial of mitomycin C plus 5-FU in the treatment of drug-refractory ovarian cancer.

Following cisplatin combination chemotherapy for advanced epithelial type ovarian cancer, response to subsequent treatments has proved relatively poor. Mitomycin C and 5-fluorouracil (5-FU) have both been reported to have useful activity as single agents in patients with drug-refractory ovarian cancer. We have carried out a phase II trial of a combination of these two agents in 25 patients who had previously received a median of two chemotherapy regimens (range, one to five regimens). Patients received mitomycin C, 10 mg/m2 intravenously (IV) on day 1 every 6 weeks, and 5-FU, 500 mg/m2 IV daily on days 1 to 3 every 3 weeks. Four patients experienced a complete response and six patients a partial response, for an overall objective response rate of 40%. The median duration of complete and partial responses was 8 and 4 months, respectively. The median duration of survival for all 25 patients was 10.5 months (range, 2.5 to 49+ months). The most prevalent toxicity was bone marrow suppression. Leukopenia occurred in 68% of the patients, and 36% experienced thrombocytopenia. Severe or life-threatening bone marrow suppression was observed in 36% of the patients and required dose reduction or drug discontinuance in 28% and 24%, respectively. We conclude that mitomycin C plus 5-FU combination therapy appears to be extremely active in patients with drug-refractory disease. Confirmatory trials are indicated.