DEVELOPMENT OF ENDOMETRIAL CANCER IN WOMEN ON ESTROGEN AND PROGESTIN HORMONE REPLACEMENT THERAPY

The presenting symptoms, hormonal regimens, treatment modalities, tumo r pathology, and follow-up of 25 women developing endometrial cancer w hile receiving postmenopausal estrogen and progestin therapy were inve stigated retrospectively. Patients were interviewed and hormone therap ies were confirmed through medical records. Pathology specimens were r eviewed. Patients received conjugated estrogens (n = 20) or another es trogen (n = 5). For those on conjugated estrogens, the mean daily dose was 0.68 mg, monthly duration was 24.9 days, and monthly dose was 17. 0 mg. Women also received medroxyprogesterone acetate (n = 23) or nore thindrone acetate (n = 2). The most common regimen was sequential medr oxyprogesterone acetate, at a mean daily dose of 7.5 mg, monthly durat ion of 9.3 days, and monthly dose of 68 mg (mean duration = 5.7 years) . Most tumors were low stage and grade, with few demonstrating grade 3 disease (n = 2) or greater than 50% myometrial invasion (n = 2). Twen ty-three (92%) had disease limited to the uterus, while two had stage IIIA disease. All are alive and disease-free after a median follow-up of 26 months. Estrogen and progestin therapy does not prevent endometr ial cancer in all patients. Women who developed this tumor on sequenti al therapy in general received less than the recommended guidelines fo r daily dosage and monthly duration of progestin. Most patients had ea rly-stage and low-grade disease. Continued vigilance in the care of wo men on hormone replacement therapy is necessary even when combination therapy is prescribed. (C) 1994 Academic Press, Inc.