Incidence and management of gynecomastia in men treated for prostate cancer

Gynecomastia is a potentially treatment limiting adverse event in men receiving hormone therapy for prostate cancer.

In large, randomized, placebo controlled studies approximately 50% or more of patients with prostate cancer experienced gynecomastia due to multiple mechanisms. Although its severity was mostly reported as mild to moderate, gynecomastia was cited as the reason for most premature withdrawals from therapy. In patients with advanced forms of prostate cancer bilateral orchiectomy was associated with the lowest incidence of gynecomastia, followed by nonsteroidal antiandrogen therapy, diethylstilbestrol and estrogen in rank order.

It is important that gynecomastia is well managed in patients with prostate cancer who want to proceed with hormone therapy. Patients should be assessed for the likely etiology of gynecomastia and preventive therapy or treatment for established gynecomastia should be instituted. Prophylactic radiotherapy has been shown to decrease the incidence of hormone induced gynecomastia by more than 50%. An alternative course of action, which may be more convenient for the patient, is the prophylactic use of tamoxifen. Tamoxifen may also mitigate or resolve gynecomastia during its early or proliferative phase. In severe long-standing gynecomastia surgery is warranted since medical therapies are less likely to succeed. Aromatase inhibitors and 4-hydroxytamoxifen are investigational.

Gynecomastia is a significant problem in men undergoing hormonal therapy for prostate cancer. It requires prompt recognition, evaluation and management.