Fluoxymesterone as third line endocrine therapy for advanced breast cancer. A phase II trial of the Piedmont Oncology...

The Piedmont Oncology Association conducted a Phase II trial of fluoxymesterone (Halotestin) in 28 patients who failed to respond to prior hormonal therapy with tamoxifen and a progestational agent. Of nine patients who had responded to prior endocrine therapy, one had a partial response (PR) as defined by strict criteria and remains on study at 17 + months for an 11% response rate [95% confidence interval (CI), complete response (CR) + PR, 0-48%]. None of 19 previously unresponsive patients achieved remission (95% CI, CR + PR, 0-18%). Eleven patients' performance status deteriorated during therapy. Five of them had not received prior chemotherapy, and their response to subsequent chemotherapy may have been adversely affected. Third-line hormonal therapy with fluoxymesterone can be recommended only as a temporizing measure in patients with indolent disease who have responded to prior hormonal therapy.