Recently, a patient asked, “Do women who are on post-menopausal hormone replacement have a higher risk of breast cancer?”
The short answer is yes, but minimal. It depends on the type of hormone and length of hormone use. The most common type of post-menopausal hormone therapy is estrogen only, and you must be on estrogen 5-10 years for it to increase your risk. If you stop taking hormones, you will soon return to normal risk. Combined therapy with estrogen and progesterone, which is less common, carries a somewhat greater risk.
How do you categorize normal and high risk?
When health care personnel talk about breast cancer risk, it is most often in terms of lifetime risk. You have heard that one out of eight women in the United States will get breast cancer during her lifetime, which means that lifetime risk is 12.5 percent. We speak of intermediate risk as lifetime risk of 15-20 percent, and high risk is lifetime risk greater than 20 percent.
How much does post-menopausal hormone therapy increase a woman’s lifetime risk of breast cancer?
A woman currently on estrogen replacement therapy will see her lifetime risk raised from approximately 12.5 percent to less than 14 percent, whereas a woman on combined estrogen-progesterone therapy will see her risk elevated to just over 16 percent. It appears that the increased risk for women on estrogen alone occurs only for women with normal weight, not for those who are overweight.
However, women who are overweight have a slight increased risk of breast cancer from the weight factor alone, so the end result is about the same. Check back soon, as we will talk more about other risk factors in a future column.
So, while there is a mild increased risk for some women who take post-menopausal estrogen, it may be a reasonable risk for you in order to relieve the symptoms of early menopause, and is reversible upon cessation of estrogen therapy. Rest assured that your physician will most likely weigh the risks and benefits carefully when recommending hormones for your health.
J. Timothy Blackwelder, MD, is board certified in diagnostic radiology, Dr. Blackwelder has had extensive training in breast imaging. He has taught digital mammography workshops for World Class CME and ultrasound-guided breast biopsy workshops for the Radiological Society of North America’s annual convention. He continues to lecture to physician and consumer groups. Prior to joining Breast Diagnostic Center full-time, he was a breast imaging specialist for Swedish Cancer Institute and the University of Kentucky. He is a senior partner at the Breast Diagnostic Centers of Auburn and Federal Way.
