An evaluation of hexamethylmelamine, cis-diamminedichloroplatinum, and mitomycin-C in advanced breast cancer. A pilot study of the Southeastern Cancer Study Group.

Eleven patients with metastatic breast cancer refractory to conventional therapy were treated with a combination of hexamethylmelamine 250 mg/m2 p.o. days 1-14, repeated at 4-week intervals; cis-platinum 30 mg/m2 I.V. q 28 days; and mitomycin-C 7.5-10 mg/m2 I.V. q 56 days. There were no complete responders and three partial responders for a response rate of 27%. Two patients (18%) had stabilization of disease for brief periods. The gastrointestinal toxicity of hexamethylmelamine was unacceptable. Recent reports that cis-platinum and hexamethylmelamine lack activity in breast cancer suggest that the activity of the combination was due to mitomycin-C alone.