Doxorubicin versus mitomycin versus doxorubicin plus mitomycin in advanced breast cancer: a randomized study

In a randomized trial the antineoplastic and toxic effects of doxorubicin (ADR), mitomycin (MMC), and the combination of the two were evaluated in postmenopausal patients with advanced breast cancer using the following treatment regimens: ADR (75 mg/m2 by iv bolus every 3 weeks); MMC (20 mg/m2 by iv bolus every 6 weeks); and ADR (45 mg/m2 by iv bolus every 3 weeks) and MMC (10 mg/m2 by iv bolus every 6 weeks). One hundred one patients were entered in the study. Entrance to single-agent MMC therapy was stopped after allocation of 12 patients because of unacceptable side effects, especially nausea and vomiting, and the suggestion of minor efficacy. One of these patients had partial response, eight had no change, and three had progressive disease. The patients in the ADR and ADR plus MMC group were similar as to the following: age (median, 60 years); menopausal age; disease-free interval; performance status, extent of previous cytotoxic therapy (approximately 90% were pretreated) and radiation therapy; and dominant site of disease but with significantly more involved organ sites in the ADR plus MMC group. Among evaluable patients (42 in the ADR group and 39 in the ADR plus MMC group), response rates were as follows: complete response--21 versus five; partial response--26 versus 44; no change--40 versus 38; and progressive disease--12 versus 13 (P greater than 0.10). Median times to disease progression were 5.2 and 7.8 months, respectively (log-rank test, P = 0.03), but survival times were similar, 9.3 and 10.2 months, respectively (log-rank test, P greater than 0.40). For the two treatment groups suppression of wbc count was similar, while anemia, thrombopenia, and nausea and vomiting were significantly more common among the ADR plus MMC-treated group. Five treatment-induced deaths were observed in the ADR plus MMC group (one from sepsis; two from diffuse hemorrhage; and two from cardiomyopathy), compared to none in the ADR group. In conclusion, this study disclosed no major advantage of the combination of ADR plus MMC compared to ADR alone as second-line treatment of advanced breast cancer, but results from other studies may imply a possible role of MMC as part of second-line combination chemotherapy regimens.