Hormone Replacement Therapy and Cancer

We've all seen the headlines:  Hormone Replacement Therapy Increases Risks for Cancer! If you're a woman using hormone replacement therapy (HRT), you may be frightened about developing cancer, but even more frightened about giving up your prescription. But hold on-things might not be as scary as they seem. 

Hormone Replacement Therapy is not a one-size-fits-all prescription. There are a variety of ways HRT is prescribed because menopausal women have different health factors to consider. Some have a uterus, some don't.  Some have ovaries, some don't. Some have severe menopausal symptoms. Some have mild ones. 

Some already have increased risk for developing breast, ovarian, colorectal, or lung cancer; others don't. Some women need estrogen and progestin and some need only estrogen. Some use a cream, patch or pill that delivers a continuous dose every day and others take different doses on different days. It's a custom-care situation where the right HRT prescription is tailored to fit the woman. 

While any form of HRT comes with some risk factors, it's up to the patient and her doctor to determine how high they are and whether it's worth it to take those chances. For many women, menopausal symptoms, including hot flashes, insomnia, mood swings, headaches, and brain fog (to name a few) are so disruptive that life without hormones is miserable.  It may even have life-altering implications like depression, anxiety, and reduced productivity. Fortunately, the many different HRT prescriptions available mean there may be a relatively safe option to keep postmenopausal women healthy and comfortable.

Recent headlines and older ones based on the Women's Health Initiative Study (2002) that report increased cancer risk are primarily focused on one kind of HRT, Prempro, a combination of the hormones estrogen and progestin used by 15 to 20 percent of postmenopausal American women.  Prempro is made from equine (horse) estrogen. A recent study reported in the Journal of American Medical Association says Prempro increased women's risk of developing breast cancer, the severity of the disease and chances of death. While this is scary information, it's important to remember that Prempro is just one kind of HRT and the increased breast cancer risks aren't a guarantee of disease and death. In fact, the increased risk is considered relatively low by some analysis.

Other forms of HRT use what's called "bioidentical" hormones that are identical in molecular structure to the hormones women make in their bodies. They're synthesized, from a plant chemical extracted from yams and soy as a combination of 17 beta-estradiol, estrone, and estriol. Bioidentical hormones are available via a pill, patch or ring form and are prescribed by gynecologists.

The American Cancer Society has broken down individual HRT types and their connection to increased cancer risks on their website. This is a thorough and reassuring analysis that may be a sigh of relief to many women who count on HRT to keep them on top of their game. 

Journal of the American Medical Association
Estrogen Plus Progestin and Breast Cancer Incidence and Mortality in Postmenopausal Women

Rowan T. Chlebowski, MD, PhD; Garnet L. Anderson, PhD; Margery Gass, MD; Dorothy S. Lane, MD; Aaron K. Aragaki, MS; Lewis H. Kuller, MD; JoAnn E. Manson, MD, DrPH; Marcia L. Stefanick, PhD; Judith Ockene, MD; Gloria E. Sarto, MD; Karen C. Johnson, MD, MPH; Jean Wactawski-Wende, PhD; Peter M. Ravdin, MD, PhD; Robert Schenken, MD; Susan L. Hendrix, DO; Aleksandar Rajkovic, MD, PhD; Thomas E. Rohan, PhD; Shagufta Yasmeen, MD; Ross L. Prentice, PhD; for the WHI Investigators

JAMA. 2010;304(15):1684-1692. doi:10.1001/jama.2010.1500

Menopausal Hormone Replacement Therapy and Cancer Risk