Another serious side effect of ERT is reflected in studies that have shown an association between estrogen replacement therapy and the development of endometrial cancer. Estrogen over stimulates the tissue lining of the uterus in menopausal women and causes uncontrolled growth.
Endometrial cancer is cancer of the lining of the uterus.
This type of cancer is the most common of the female reproductive system. When left untreated, endometrial cancer can spread to the muscle wall of the uterus. In addition to ERT, several more risk factors have been identified in developing endometrial cancer. These include being over the age of 50, hormone replacement therapy, being overweight, suffering from diabetes or high blood pressure, taking tamoxifen, which is a drug to treat breast cancer, or being a caucasian woman. Other factors include estrogen-producing tumors, early age of menstrual period, late menopause, never having children, a history of infertility, or not ovulating.