Therapeutic activity of testosterone in metastatic breast cancer.

Hormone therapy plays an important role in the management of breast cancer. In the past, testosterone was the most common line of hormonal therapy for this disease, but its use has been almost completely abandoned in the past 40 years. However, because of earlier reports on favorable therapeutic results, we re-evaluated its use for treatment of hormone-responsive patients who have become refractory to other lines of hormonal therapy.

Fifty-three consecutive patients with positive metastatic breast cancer who had become refractory to treatment with other hormones and whose disease was progressing, were treated with testosterone propionate, 250 mg once every two weeks, twice, and then once every four weeks until disease progression, drug toxicity, or death.

Regression of disease was seen in 9 patients (17%; 2% complete and 15% partial). Stabilization of disease was seen in 22 patients (41.5%). In the remaining 22 patients (41,5%), the disease progressed. Median overall survival was 12 months from beginning of testosterone treatment. Hirsutism and dysphonia were noted occasionally, but were not distressing enough to mandate cessation of treatment. There was no major toxicity except for two non-fatal pulmonary emboli.

Testosterone showed a significant therapeutic activity in previously hormone-treated patients with metastatic breast cancer who were no longer responding to such treatment and whose disease was progressing. These results warrant consideration of testosterone use as treatment for patients with hormone-sensitive metastatic breast cancer.