[Long-term study of women with biopsy-proven mastopathy].

Out of a total of 1306 women (average age 42 years) with a biopsy proven mastopathy, manifest ipsilateral carcinoma occurred in 13 during the following 6 years. Thus the incidence of carcinoma differed little from the expected number of new cases in women of a comparable age. However, subdivision of breast lesions into simple (n = 1052) and proliferative (n = 254) forms showed that the carcinoma risk is double in proliferative mastopathy and fourfold higher when mastopathy with atypical epithelial proliferation is considered. An association with contraceptive hormones was not seen.