Research has shown that using hormone replacement therapy (HRT) increases the risk of breast cancer. A large study found that women who took estrogen HRT after menopause were about twice as likely to develop benign (not cancerous) breast disease as women who didn't take estrogen HRT.
This large study looked at more than 10,000 women, about half of whom received estrogen HRT. The other half received a placebo. The women were followed for about 7 years.
Cysts and fatty tumors that aren't cancer are examples of benign breast disease. Benign breast disease can be found during self-exam, an exam by a doctor, or by a mammogram. Benign breast disease is NOT cancer and is NOT life threatening. But finding benign breast disease can be scary and disruptive to your life. Your doctor might recommend a biopsy or surgery to diagnose and remove the benign disease. Waiting for the results of a biopsy or other tests is always stressful until you find out that the lump isn't cancer.
Menopausal symptoms can dramatically reduce quality of life for some women. If this is happening to you, you have to weigh the benefits of HRT against the risks. In addition to an increased risk of breast cancer, the results reported here suggest that using estrogen HRT also can increase a woman's risk of benign breast disease.
If you're considering HRT, talk to your doctor about your options. Be sure to discuss the pros and cons of different types of HRT. Estrogen-only HRT (which was used in this study) appears to increase breast cancer risk less than combination HRT (which contains estrogen and progesterone). Together, you and your doctor can decide if HRT or another treatment for menopause might be right for you.
If you do decide to take HRT, try to use it for the shortest time possible. One study found that breast cancer risk didn't go up significantly when women took combination HRT for fewer than 3 years.
You can also take other steps -- such as eating healthy, nutritious food, and exercising every day -- that can lower your breast cancer risk. Regular breast self-exams, annual exams by your doctor, and routine mammograms also are very important to detect both benign breast disease and breast cancer early.