IMPACT OF MENOPAUSAL HORMONE-REPLACEMENT THERAPY ON CLINICAL AND LABORATORY CHARACTERISTICS OF BREAST-CANCER

Hormone-replacement therapy (HRT) is widely used by post-menopausal wo men. Although this treatment may slightly increase the incidence of br east cancer, more and more cases are diagnosed while women are taking HRT. The purpose of this study was to ascertain the influence of HRT o n prognostic factors and outcome of breast cancer. Data on all breast- cancer patients, including precise information on HRT, was prospective ly and systematically recorded in a data base. From 1985 to 1995, 1379 post-menopausal women fulfilled the eligibility criteria for this stu dy. AII were treated by us (P.B. and L.P.) in our ward of a large publ ic hospital of Marseilles, France. The clinical features, laboratory f indings and survival rates in 142 HRT users who developed breast cance r while being treated were compared with those of 284 matched never us er breast-cancer patients, patients who developed breast cancer during HRT had fewer locally advanced cancers and smaller and better-differe ntiated cancers. Lymph-node involvement was significantly less frequen t in the user group than in the non-user group (non-significant). Estr adiol receptivity was both qualitatively and quantitatively lower in u sers. There was no significant difference with regard to recurrence an d metastasis-free survival and overall survival. We conclude that HRT does not affect the prognosis of breast cancer. Regular surveillance d uring HRT allows early defection of smaller lesions. The higher number of well-differentiated cancers and the distribution of hormone recept ivity may reflect interaction between neoplastic tissue and exogenous hormones. (C) 1998 Wiley-Liss, Inc.