Most
male breast cancer tumours are
hormone receptor-positive; the patients therefore receive endocrine
therapy. There is, however, a paucity of published data on toxicities experienced by
male breast cancer patients who are prescribed endocrine
therapy. In the present study, we examined rates of adherence to and toxicity from endocrine treatments in
male breast cancer patients treated at a single institution.
PATIENTS AND METHODS: We conducted a retrospective study of male patients diagnosed with
breast cancer at The Ottawa Hospital Cancer Centre during 1981-2003. Data collected included patient age,
hormone receptor status,
therapy adherence, self-reported toxicities, and type and duration of endocrine
therapies.
RESULTS: The review located 59 cases of early-stage and metastatic
male breast cancer. Median patient age was 68.0 years.
Tamoxifen was given to 38 patients (64.4%),
anastrozole to 8 (13.6%), and
letrozole to 5 (8.5%). Of patients who received endocrine
therapy, 10 (25%) received adjuvant systemic
chemotherapy. Toxicity was reported by 19 patients taking
tamoxifen (50%), with
hot flashes being the most common complaint (18.4%). Decreased libido,
weight gain, and malaise were reported by 5 patients (13.2%).
Rash and
erectile dysfunction were reported by 3 patients (7.9%). Increased liver
enzymes,
pulmonary embolism, superficial
thrombophlebitis,
myalgia, depression, visual blurring, and loose stools were each reported in 1 patient (2.6%).
Tamoxifen therapy was discontinued secondary to toxicity in 9 patients (23.7%). Of the patients treated with
anastrozole, 3 (37.5%) reported toxicity, with 1 report each of decreased libido, leg swelling, and depression (12.5%). Toxicity was reported in 2 patients taking
letrozole (40%), with both reporting peripheral
edema, and 1 reporting
hot flashes. No patient discontinued
anastrozole or
letrozole because of toxicity.
CONCLUSIONS: Few studies specifically report data on adherence to and toxicities from endocrine
therapies in
male breast cancer patients. The rate of discontinuation at our institution because of toxicity (23.7%) is similar to that reported in the female
breast cancer population. Future prospective studies should explore strategies to improve adherence to endocrine
therapy in this population.