Intramuscular depot medroxyprogesterone versus oral megestrol for the control of postmenopausal hot flashes in breast cancer patients: a randomized study

Background: Hot flashes are frequent in postmenopausal breast cancer patients, especially when treated with tamoxifen. Estrogen replacement therapy is the most effective treatment for hot flashes, but its use is controversial in breast cancer survivors. Progestins may offer a good alternative for the control of hot flashes in this setting; in particular, oral megestrol acetate has been proven effective in a randomized, placebo-controlled clinical trial. With the aim of further improving these results, we have designed a randomized study comparing oral megestrol acetate with depot intramuscular (i.m.) medroxyprogesterone acetate (MPA) for the control of hot flashes in postmenopausal patients with a history of breast cancer. Patients and methods: Seventy-one postmenopausal patients were randomized to receive an i.m. injection of depot MPA 500 mg on days 1, 14 and 28, or oral megestrol acetate 40 mg daily for 6 weeks. Patients recorded daily the number and severity of their hot flashes; response was defined as a greater than or equal to50% decrease in the number and severity of hot flashes. Results: At week 6, hot flashes were reduced by 86% on average in the whole group of patients, without significant differences between the two progestins. Response was obtained by 75 and 67% of patients receiving MPA or megestrol, respectively P = 0.5). Responders were followed to assess maintenance of response (without further treatment), which was significantly better with i.m. MPA: in this group, 89% of responders still showed a benefit at week 24, compared with 45% in the megestrol group (P = 0.03). Conclusions: Our study shows that a short cycle of i.m. depot MPA injections provides significant and long-lasting relief from postmenopausal hot flashes in patients with a history of breast cancer, offering an alternative to estrogen replacement therapy or prolonged administration of oral megestrol.