Mass screening of asymptomatic women for endometrial cancer has never been shown to reduce morbidity or mortality from the disease. In 801 perimenopausal and postmenopausal women who had a baseline endometrial biopsy before enrolling in a study of estrogen-progestin replacement, only one metrial cancer (0.13%) was found (Archer). Conversely, in another study, screening 2586 asymptomatic women with endometrial cytologic aspirates, 6.96 cancers per 1000 women were found (Koss). From 1949 to 1965, Hofmeister performed 14,655 endometrial biopsies, often in asymptomatic women. He detected 122 malignancies, of which 102 were endometrial adenocarcinomas. Twenty-two of the endometrial adenocarcinomas were asymptomatic (Hofmeister). At present, neither the Canadian Task Force on the Periodic Health Examination nor the U.S. Preventive Services Task Force recommends screening of asymptomatic women for uterine cancer.