[Hormonal replacement therapy and breast cancer. A case-control study].

Aims: Breast cancer is the second more frequently neoplasia in the woman and the first cause of mortality after 35 years old. It is considered a multifactorial illness, since is influenced for genetic, dietary and endocrine factors. Among these, hormonal replacement therapy (HRT) have been assigned benefits effect, as well as risks to increase the breast cancer incidence, because presence of estrogens receptor in the neoplasia cells makes think that the estrogens and other sexual hormones constitute a factor promoter of this cancer.