[Anti-steroid hormones for uterine cancer]

Endometrial cancer is an estrogen-dependent tumor with increasing incidence in recent years. It can be classified into two types: the more common type 1 tumors are estrogen-dependent, develop in relatively younger patients, and are associated with a relatively good prognosis; while type 2 tumors are estrogen-independent, develop in relatively older patients and are associated with a poorer prognosis. On the other hand, with the increase in breast cancer patients in recent years and with the resulting similar increase in patients on oral tamoxifen treatment, there has been a problematic rise in the incidence of endometrial cancers induced by tamoxifen use. This has necessitated a need for careful observation of these patients as tamoxifen-related endometrial cancers are often type 2 cancers and thus present with a poorer prognosis. A large number of hormonal treatments have been used in the treatment of endometrial cancer; however, only progestin derivatives have demonstrated any effect towards endometrial cancer to date. In general, progestin therapy is used only for fertility-preserving purposes in younger patients. These patients must fulfill the indications of well-differentiated endometrioid adenocarcinoma of Stage Ia; in these patients, medroxyprogesterone acetate (MPA) 400-600 mg/day is administered and treatment effects are evaluated by endometrial biopsy every 8 weeks.