Controlled release systems and low dose androgens

A method of treating or preventing endometrial cancer comprising administering to a patient in need of such treatment or prevention, an effective amount of sustained release particles, with or without additional pharmaceutical carriers or diluents, said particles comprising an androgenic steroid selected from the group consisting of medroxyprogesterone acetate or megestrol acetate, wherein said androgenic steroid is dispersed within a sustained-release binder which is biocompatible with human tissue and which undergoes biodegradation in the body into biocompatible metabolic products, wherein said particles are capable, under standard conditions, of releasing said androgenic steroid during and as result of said biodegradation of said binder at a rate and duration which maintains circulating serum levels of said androgenic steroid between 1.0 and 50.0 nanomoles per liter during a time period beginning 48 hours after administration and ending at least 28 days after administration.