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 differentreceptors and may therefore have complementary effects againsthuman breast cancer. This possibility was tested in a randomizedstudy which compared the effects of tamoxifen, standard-dosemegestrol acetate, and these two agents in combination, in patientswith metastatic breast cancer. PATIENTS AND METHODS:: 184 post-menopausal patients with metastatic breast cancer wererandomized to initial treatment with either tamoxifen (TAM)40 mg daily, megestrol acetate (MA) 160 mgm daily, or the combinationof the two administered simultaneously. Patients crossed overto the alternative single agent on relapse or disease progression.Patients were evaluated for response, time to initial and ultimatetreatment failure, and survival. RESULTS:: There were no significant differences between the three groupswith respect to response rates, nor the other parameters. Patientsurvival was significantly associated with age >60 years,ER positive status, and the absence of visceral metastases. CONCLUSIONS:: TAM and MA are both equally effective in response inductionas initial treatments and the combination has no advantage.Sequential treatment is still optimal, TAM being the preferredinitial agent in view of the reported side effects with MA. breast, cancer, megestrol acetate, randomized, trial, tamoxifen