Impact of Hormone Replacement Therapy on Breast Cancer

The use of hormone replacement therapy (HRT) and its effect on women's health are contentious issues and have been for as long as HRT has been prescribed. The use of HRT for the treatment of the symptoms of menopause is widespread and well recognized. However, the exposure to exogenous hormones in postmenopausal women and the subsequent risk of cancer in general, and breast cancer in particular, have been of interest. The reproductive life of women is marked by menarche at puberty and menopause in middle age. The definition of menopause is the cessation of menstruation as a result of ovarian failure and signifies the end of a woman's reproductive life. Ovarian failure in turn leads to decreasing circulating levels of estrogen, and the result of which is the manifestation of the acute symptoms of the menopause. These symptoms most commonly include bleeding irregularities, vasomotor, and urogenital symptoms (Critchley et al. 2005a). © 2010 Springer-Verlag London