Some recent studies of women who took estrogen combined with progestin have shown them to be at increased risk of developing breast cancer, while others have shown them not to be. Still other evidence suggests that the risk of breast cancer is increased in current users of HRT, but not in those who used HRT in the past. Doctors are concerned that the exposure to estrogen in HRT might increase their risk for recurrence. A relationship has also been identified between long-term use of HRT and endometrial cancer. But adding progestin to HRT has been found to substantially reduce the risk of endometrial cancer associated with taking estrogen alone.
Some women report side effects, such as experienced bloating and breast tenderness.
Scientists are continuing to gather information to define the potential risks and benefits from HRT and to identify the women for whom it may be most useful. Further research will also be needed to show when HRT should be started and how long it should be continued to achieve the greatest benefits. Trouble Signs Physicians usually caution women not to use HRT if they are already at high risk for developing blood clots. Obesity, severe varicose veins, smoking, and a history of blood clots would place you at high risk for blood clots. Inc. National Institutes of Health, National Institutes on Aging, Menopause, December 1992.