Methylxanthines and benign breast disease.

The relation between methylxanthine consumption and biopsied benign breast disease was investigated by using data from a case-control study which included 1,569 cases and 1,846 controls identified between 1973 and 1980 through a nationwide screening program. There was no evidence of an association between methylxanthine consumption and benign breast disease in the total study population. When histologic types of benign breast disease were examined, there were no trends in risk according to methylxanthine consumption among the 813 cases with fibrocystic disease, the 508 cases for whom detailed pathology data were not available, the 172 cases with benign neoplasms, or the 156 cases with other benign conditions. When cases with fibrocystic disease were examined according to presence of atypia, hyperplasia, sclerosing adenosis, or cysts, there was, again, no association between methylxanthine consumption and risk of disease. In addition, no relation was found between methylxanthine consumption and menstrual breast tenderness among premenopausal women with fibrocystic disease or unknown conditions.