HRT: Revisiting the Hormone Decision
It's been 5 years since studies proclaimed hormone replacement therapy a danger for women. WebMD investigates today’s changes and tells you what you need to know to make the HRT decision.
HRT and Breast Cancer
While the impact of HRT on the heart may seem less ominous today than in 2002, links to breast cancer are less clear -- and some say less encouraging.
Many experts say that more than coincidence was at work when, in the years following the WHI announcement, women stopped taking hormones en masse -- and the incidence of breast cancer subsequently declined.
"A drop in hormone use may not have been the sole reason we saw fewer breast cancers, but I am certainly convinced it played a significant role," says Julia Smith, MD, director of the Lynne Cohen Breast Cancer Preventive Care Program at the NYU Medical Center in New York City.
But Smith says the back-story linking hormone use and breast cancer goes far beyond just connecting a few incriminating dots. It's a complex relationship, she says, that is still not fully explained – or explainable.
"What we have learned since the WHI is that for most women taking hormones short term -- for two or three years for symptom relief -- there won't be an increase in breast cancer in the short term, but this doesn't necessarily mean these women won't see an increase in breast cancer in the long term," says Smith.
Stuenkel tells WebMD even Mother Nature validates this line of thinking.
"Population studies for a women who go into menopause at age 55 instead of 50, there is an overall increased risk of breast cancer, so the duration of hormone stimulation definitely matters," says Stuenkel. Indeed, the WHI showed breast cancer risks clearly increased the longer a woman remained on HRT.
At the same time, however, Goldstein notes that at least one reanalysis of the WHI findings published in JAMA in 2006 found that women who had a hysterectomy and used estrogen-only therapy for an average of seven years had no increase in breast cancer rates.
"In fact, risks of at least one type of breast cancer were reduced in these women," says Goldstein.
But again, Stuenkel reminds us that the duration of hormone use might change that picture, too. She points to results from the Harvard Nurses' Health Study published in the Archives of Internal Medicine in 2006, which reported that those women who took estrogen only experienced an increase in breast cancer after 20 years of use.
"I have not bought into the idea that estrogen alone reduces breast cancer, and for me the duration of exposure is still a key issue – when it comes to HRT, I just don't believe there's going to be a free lunch for any woman," says Stuenkel.