Mitomycin-C and megestrol acetate in treatment of breast cancer refractory to hormonal and combination chemotherapy.

Fifty patients with breast cancer refractory to endocrine manipulation and/or combination chemotherapy were treated with mitomycin-C 20 mg/m2 I.V. every 4-6 weeks and megestrol acetate 160 mg daily. Of 48 evaluable patients, 4% achieved complete remission (CR), 23% had partial remission (PR). Median duration of response for CR and PR was 7 months. Non-responders had a median survival of 2 months. The difference in survival of responders (both CR and PR) and non-responders was statistically significant at p less than 0.01 level. Attenuated doses of mitomycin-C were administered at increasing intervals due to cumulative myelosuppressive toxicity.