Clinical evaluation of estramustine phosphate in the treatment of patients with advanced breast cancers

: Estramustine phosphate, an anti-prostatic cancer agent, was investigated on eleven patients to evaluate the efficacy in a treatment of advanced breast cancers. The daily dose of medication was 840 mg. According to criteria of Japan Society for Cancer Therapy, none was assessed as CR, three as PR, four as NC and PD. The response rate was 27.3%. There was no differences in response rates among estrogen receptor status. A favourable response was observed in postmenopausal patients but no response in premenopausal, as well as a good response in lesions of soft tissue and lung, a poor response in lesions of liver and bone. As to toxicity of estramustine phosphate, gastrointestinal disorders such as nausea, vomiting and diarrhea were noted frequently during the treatment, and a long term administration was not able to perform in premenopausal patients because of vaginal bleeding and discharge, and pain in breast. The estramustine phosphate therapy for advanced breast cancers was regarded as one of modalities for a treatment of postmenopausal patients as a second line therapy. This is the first report in Japan discussing the efficacy of estramustine phosphate for a treatment of breast cancer.