Antitumor Efficacy of 7β, 17α-Dimethyltestosterone (Calusterone) in Advanced Female Breast Cancer

Twenty-two women with far advanced, hormone-refractory breast cancer were treated with 7β,17α dimethyltestosterone (calusterone), 150 to 300 mg per day by mouth, to test its antitumor efficacy. Using the strict criteria of the Cooperative Breast Cancer Group, 14 of the women (64 percent) obtained objective regressions. Regressions lasted for from 3 to 20 months, averaging 7 months. Undesirable actions are those of a 17α-alkylated, weak androgen with inconstant bromsulphalein retention, but without elevation of serum bilirubin levels or of hepatic enzymes. This compound has potent antitumor efficacy in women with advanced breast cancer, is better tolerated than most chemotherapeutic or steroidal antitumor agents, and will probably assume an important position in the care of these patients.