Progestational agents in advanced breast cancer: an overview

Abstract

Progestational agents, such as megestrol acetate and medroxyprogesterone acetate, are effective hormonal treatments for metastatic breast cancer in postmenopausal women. Clinical trials of these agents have demonstrated that 30% to 60% of patients will experience objective tumor response, depending on pretreatment prognostic variables. Although optimal doses and schedules have not been fully defined, current studies are investigating the therapeutic effectiveness of high-dose progestins. Toxicity of these drugs is mild and generally limited to weight gain related to their anabolic activity. Progestins are active second-line agents for metastatic breast cancer in postmenopausal women. In selected patients, they appear to be equivalent to tamoxifen as first-line therapy for metastatic disease. As more patients are exposed to prolonged adjuvant tamoxifen therapy, the role of progestins as first-line hormonal therapy at the time of relapse is likely to expand.