RANDOMIZED COMPARISON OF THE EFFECTS OF TAMOXIFEN, MEGESTROL-ACETATE,OR TAMOXIFEN PLUS MEGESTROL-ACETATE ON TREATMENT RESPONSE AND SURVIVAL IN PATIENTS WITH METASTATIC BREAST-CANCER

Background: The antioestrogen tamoxifen and progestins act via differe nt receptors and may therefore have complementary effects against huma n breast cancer. This possibility was tested in a randomized study whi ch compared the effects of tamoxifen, standard-dose megestrol acetate, and these two agents in combination, in patients with metastatic brea st cancer. Patients and methods: 184 post-menopausal patients with met astatic breast cancer were randomized to initial treatment with either tamoxifen (TAM) 40 mg daily, megestrol acetate (MA) 160 mgm daily, or the combination of the two administered simultaneously. Patients cros sed over to the alternative single agent on relapse or disease progres sion. Patients were evaluated for response, time to initial and ultima te treatment failure, and survival. Results: There were no significant differences between the three groups with respect to response rates, nor the other parameters. Patient survival was significantly associate d with age >60 years, ER positive status, and the absence of visceral metastases. Conclusions: TAM and MA are both equally effective in resp onse induction as initial treatments and the combination has no advant age. Sequential treatment is still optimal, TAM being the preferred in itial agent in view of the reported side effects with MA.