After HRT, Some Health Risks Remain
Researchers Examine Pros and Cons of Hormone Replacement Therapy
WebMD News Archive
HRT and Health Risks: Findings continued...
The risk for cardiovascular problems, including heart attacks, strokes, and
lung blood clots, was comparable for the former users and the nonusers.
While former HRT users had 343 such "events," nonusers had 323.
After the HRT was stopped, the risk of fractures was similar among former
users and nonusers, indicating the protective effect of the hormones
disappeared once they were stopped. The rates of colorectal cancer didn't
differ in a significant way between the two groups, either, indicating the
protective effects found with HRT against colorectal cancer disappeared,
The risk of breast cancer stayed elevated during the follow-up. "Women
on HRT had a 27% increased risk" of breast cancer compared to nonusers,
Chlebowski says. While 79 former HRT users developed breast cancer during the
follow-up, 60 nonusers did. However, the differences are not statistically
significant, Chlebowski says.
When looking at the breast cancer risk, say Heiss and Chlebowski, it may
have been a bit too soon for the breast cancer risk to decline. "We do see
a tendency toward the breast cancer risk going down," Heiss tells
The other troubling cancer finding: "Women on HRT had a 24% greater risk
of all [invasive types of] cancer compared to women on placebo," Heiss
says. While 281 of the former HRT users developed cancer during the follow-up,
218 nonusers did. Still, Heiss says, "that is not overly alarming."
Chlebowski says the finding is "concerning" and warrants more study.
Why other cancers, including lung
cancer, were more common among former HRT users than nonusers is a mystery,
Another Expert Weighs In
The new study does have some good news, says James Liu, MD, chairman of
obstetrics and gynecology at MacDonald Women's Hospital, Case Medical Center,
University Hospitals, Cleveland, who reviewed the findings for WebMD. Until
2001, Liu was one of the principal investigators for the Women's Health
"The good news is that the effects for the vast majority of side effects
appear to reverse," he says. "The breast cancer issue may take longer
HRT and Health Risks: Advice for Former Users
Women who took HRT should pay close attention to cancer screenings such as
mammograms and colorectal cancer screening, Chlebowski says.
Women who are still taking HRT should re-evaluate their need for it with
their doctor periodically, Liu says. "If they are still on it, I think they
need to ask the question, why are they still on it? If they are still
symptomatic [with menopausal symptoms] they need to continue their breast
The findings apply only to the combined HRT; results of the follow-up of
women who took estrogen-only are expected later.
Pharmaceutical Company Views
The hormone regimen used in the WHI study is quite different than the
typical regimen prescribed these days, according to representatives speaking at
a teleconference sponsored by Wyeth Pharmaceuticals, which makes the HRT used
in the WHI study. The typical duration of treatment has declined, according to
Wyeth, and the doses are typically lower than those used in WHI.
Currently, HRT is prescribed to women younger than those in the WHI study,
according to Wyeth. The average age of WHI participants was 63 at the start of
the study. The risks associated with older women are not the same as in younger
women, according to Gary Stiles, MD, chief medical officer and executive vice
president of Wyeth Pharmaceuticals in Philadelphia.
The study results, according to Wyeth, should be reassuring to women who use
hormone therapy during the "hard" stages of menopause, when symptoms
are most bothersome.