Estrogen Replacement Therapy in Treating Women With Early-Stage Endometrial Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed grade I, II or III endometrial adenocarcinoma (endometrioid, villoglandular, mucinous, adenosquamous, papillary serous, clear cell, or not otherwise specified) * Must have had total hysterectomy and bilateral salpingo-oophorectomy within past 20 weeks * Surgical stage IA, IB, IC, IIA (occult), or IIB (occult) disease * Must have had normal mammogram, or a negative breast biopsy after an abnormal mammogram, within past year PATIENT CHARACTERISTICS: Age: * Not specified Performance status: * Not specified Life expectancy: * Not specified Hematopoietic: * Not specified Hepatic: * Bilirubin no greater than 1.5 times normal * SGOT no greater than 3 times normal * No acute liver disease Renal: * Not specified Cardiovascular: * No prior thromboembolic disease Other: * No prior or current carcinoma of the breast * No other prior invasive malignancy within the past 5 years except nonmelanoma skin cancer PRIOR CONCURRENT THERAPY: Biologic therapy: * Not specified Chemotherapy: * Not specified Endocrine therapy: * No concurrent hormonal therapy Radiotherapy: * Not specified Surgery: * See Disease Characteristics * Recovered from prior surgery Other: * No prior cancer treatment that would preclude study therapy * Concurrent participation on GOG Lap-1 or GOG Lap-2 allowed