Risk factors for histologically confirmed benign breast tumors.

A case-control study of 156 cases of various types of benign breast disease (BBD) and 156 population controls was conducted to investigate the role of various behavioral, reproductive, and hormonal factors in the etiology of these breast disorders. Our results indicate that the distinct histological groups of BBD differ from each other in respect to possible risk factors. Small sample size poses severe restrictions on the conclusiveness of the results and thus they should be considered as preliminary and suggestive. Our results do not support the notion that BBD could be considered as a uniform entity with common risk factors.