Megestrol acetate v tamoxifen in advanced breast cancer in postmenopausal patients.

One hundred six postmenopausal patients with advanced breast cancer received megestrol acetate or tamoxifen as primary therapy. Response to therapy was comparable for the two agents, with no organ site preference observed for either agent. The median duration of remission was also comparable for the two agents. Both treatments were well tolerated, with weight gain being the most common side effect observed. Initial results of another ongoing study suggest that megestrol acetate is as effective as tamoxifen in hormone-sensitive breast cancer in which receptors have been identified.