Mammography in women undergoing hormone replacement therapy. Possible effects revealed at routine examination

A retrospective study of screen-film mammographs was performed in 960 postmenopausal women to evaluate the possible effects of hormonal replacement therapy on the breast parenchymal pattern.

Screen-film mammographs of 754 women (mean age 51.4 years) who had undergone hormonal replacement therapy (estrogen, gestagen; mean duration 2.4 years) were compared with findings in 206 women who had not received hormonal replacement therapy (mean age 52.3 years). Mastopathic changes were analyzed according to a 4-grade scale and the incidence of circumscribed lesions (such as fibroadenomas, cysts and malignancies) was further evaluated.

In the treated women we found moderate mastopathic changes in 47.2%, intermediate changes in 2.4%, and extensive proliferations in 0.7%. For the untreated women the corresponding figures were 33.5%, 4.8%, and 1.4%. In the treated patients fibroadenomas were apparent in 3.9%, cystic lesions in 3.3%, and malignant lesions in 1.4%. In the untreated women fibroadenomas were evident in 11.6%, cystic lesions in 7.2%, and malignant lesions in 2.4%.

Mastopathic changes might increase under hormonal replacement therapy. However, the higher incidence of circumscribed lesions in the untreated women might be due to the higher number of symptomatic women who sought examination. We also speculate as to whether the increased density of the breast parenchyma in the treated women might cause a higher number of mammographically undedectable lesions.