Strategies to reduce the incidence of endometrial cancer in postmenopausal women

OBJECTIVE: The purpose of this study was to develop strategies to reduce the incidence of endometrial cancer in postmenopausal women by reviewing methods to diagnose women at risk and providing therapies that are effective. STUDY DESIGN: A literature search for studies between 1975 and 1995 of the association between hormone therapy and endometrial cancer was performed with MEDLINE. There were nine reports with a total of 66 cases of endometrial cancer developing during use of estrogen-progestogen replacement therapy. RESULTS: The cases of endometrial cancer diagnosed during use of estrogen-progestagen therapy because of abnormal bleeding occurred when the dosage or duration of the progestogen was less than that considered optimum. The minimum effective dosage of medroxyprogesterone acetate is 10 mg and the minimum effective dosage of norethindrone acetate to 2.5 mg. The minimum effective duration of the progestogen is 12 to 14 days when it is used sequentially. Continuous combined therapy with low dosage estrogen and progestogen may not be fully endometrial protective. CONCLUSIONS: The progestogen challenge test is an effective test to identify women at increased risk for endometrial cancer. There are no adverse effects on lipids and lipoproteins from added progestogen when adequate dosages of estrogen are given. Side effects of progestogens can be managed with mild diuretics or by changing the type, dosage, or route of administration. Cyclic combined therapy may be more endometrial protective than continuous combined hormone replacement is.