Background: Although an uncommon disease, male breast cancer (MBC) will be responsible for 300 deaths in 1993 in the United States. Because of the high rate of estrogen receptor positivity in males, adjuvant hormonal therapy with tamoxifen in the adjuvant setting has been used widely. Little is known about the side effects of this estrogen receptor blocker in males.
Methods: The authors evaluated the side effects of adjuvant tamoxifen treatment in 24 patients (19 of whom were estrogen receptor positive) treated at the authors' institution between 1990 and 1993.
Results: Fifteen (62.5%) patients reported at least one side effect. The most common side effect was a decrease in libido, which occurred in 7 (29.2%) patients; followed by weight gain, which occurred in 6 (25%) patients; hot flashes, which occurred in 5 (20.8%); mood alterations, which occurred in 5 (20.8%); depression, which occurred in 4 (16.6%); insomnia, which occurred in 3 (12.5%); and deep venous thrombosis, which occurred in 1 (4.2%). Five (20.8%) patients terminated treatment with tamoxifen in less than 1 year because of these side effects. Two of these patients had decreased libido, two had hot flashes, and one suffered deep venous thrombosis.
Conclusions: In contrast to female breast cancer patients, who have a 4% attrition rate to adjuvant tamoxifen treatment, MBC patients have a 20.8% attrition rate related to side effects of tamoxifen treatment.