Metabolism of endogenous estrogens and breast cancer

Breast cancer is the most frequent cancer in development countries women. Although Uruguay does not belong to these countries, breast cancer incidence and mortality are extremely high. Age adjusted mortality rate from 1993 to 1997 was 25.1 per 100,000 women/year, one of the highest worldwide, thus breast cancer is a serious public health problem in Uruguay. Association between breast cancer and replacement hormonetherapy is well-known. Many studies, especially the WHI (Women's Health Initiative), have proved a higher risk due to use of estrogens. Overworld use and indication have diminish since cardiovascular risks of strogenic therapy in climateric disfunctions were added to breast cancer risk. Hormone-associated breast cancer pathogenesis do not only include external administration hormones: endogenous estrogens play an important role in causing that cancer and everyday life situations where breast cancer risk factors are associated with endogenous estrogens. The paper reviews estrogen metabolism and breast cancer association since estrogen metabolites have different biological reactions and opposite incidence in cancer risk. 2-alfa hydroxyestrone production is associated with a 40% decrease of developing breast cancer. The association diet change-estrogen production is analysed, diet changes are suggested to reduce breast cancer incidence.