Prognosis of breast cancers detected in women receiving hormone replacement therapy

Objective: To determine the influence of hormone replacement therapy (HRT) on various prognostic factors of breast cancer (BC). Methods: A multi-centre case-control study was conducted, in which a comparison was made of the differences between various histological and biological clinical variables of BC detected in 121 women undergoing HRT. at the time of diagnosis, and those cancers detected in 121 women of similar age not undergoing HRT. The variables were also analysed in function of the type of HRT and the length of time treated. Results: The tumours detected in patients receiving HRT presented significantly lower tumoural stages, a lower degree of affected axillary lymph node dissemination, and a greater percentage of well-differentiated tumours and positive estrogen receptors than those detected in women not under HBT. Most of these results due principally to those patients who were undergoing a combined treatment of estrogens and progesterones. The longer the time of HRT received, the more significantly reduced the tumoural stages observed. Conclusions: Although the better prognosis of tumours detected in women receiving HRT may be due largely to their diagnosis at earlier stages, there is an increasing body of data leading one to think that these tumours present certain histological and biological characteristics that make such cancers less aggressive. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.