TUESDAY, Oct. 19 (HealthDay News) -- Not only does prolonged use
of hormone replacement therapy raise the risk of breast cancer, new
research finds, but it also ups the risk for more severe forms of
the disease and increases a woman's chances of dying.
A study appearing in the Oct. 20 issue of the
Journal of the American Medical Association is at odds with
previous observational studies that had suggested a raised risk of
breast cancer, but only for less aggressive and more treatable
tumors. The researchers added that this is the first time an
increase in mortality has been shown.
The findings apply only to estrogen-plus-progestin, or combined
hormone therapy, not estrogen-alone therapy.
"It looks like all categories of breast cancer are increased," said study author Dr. Rowan Chlebowski. "The preponderance of observational studies had suggested that the cancers would have a more favorable outcome but now we're seeing all categories of cancer increasing and, for the first time, we're reporting mortality."
The findings may raise the bar for clinicians counseling
patients about the use of postmenopausal hormone replacement
therapy (HRT), or at least the combined form of the therapy.
"It definitely affects how we counsel people," said Dr. Elizabeth Poynor, a gynecologic oncologist and pelvic surgeon at Lenox Hill Hospital in New York City. "The only reason to go on HRT now is to control symptoms of menopause in women who can't have their symptoms controlled by non-hormonal methods. The risk-benefit is always highly individualized, so this will definitely be a component of my conversations with my patients moving forward."
"This reinforces the message that women should take the lowest dose possible for the shortest duration possible," added Chlebowski, who is a medical oncologist with the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center. "Maybe women should consider talking to their physician about stopping after a certain period of time on hormone therapy."
The now legendary Women's Health Initiative (WHI) was abruptly
halted in 2002 after researchers reported an increased incidence of
breast cancer in women taking combined estrogen-plus-progestin.
The original WHI involved 16,608 postmenopausal women aged 50 to
79 who still had their uterus. Participants were randomly assigned
to take combined HRT or a placebo.
Now, with 11 years of total follow-up, Rowan and his colleagues
found that women taking the combined HRT were 25 percent more
likely to have an invasive breast cancer than women in the placebo
group, were 78 percent more likely to have cancer that had spread
to the lymph nodes and were almost twice as likely as the placebo
group to die of breast cancer. They were also 57 percent more
likely that women in the placebo group to die from any cause after
receiving a diagnosis of breast cancer.
Put another way, there were more deaths from breast cancer (2.6
vs. 1.6 deaths per 10,000 women per year) and more deaths from any
causes (5.3 vs. 3.4 deaths per 10,000 women per year),
respectively, in the HRT group compared to the women taking a
Hormone replacement therapy use did drop off after the surprise
2002 findings, from 35 percent to 40 percent of postmenopausal
women to about 15 percent to 20 percent, Chlebowski said.
"But that is still tens of millions of prescriptions per year," he said.
And pushing the numbers down further in the United States (many
other countries already have dramatically lower rates of use) will
require some work, Chlebowski said.
"The gynecological community has been prescribing this for years, and for years it was thought to be beneficial [on heart risk, for instance]," he said. "The conjugated equine estrogens [used in combination with progestin in this study] were introduced into U.S. practice in 1942, so that's a long time."
But, to many experts, the risks seem more apparent than
"This study goes even further to discourage the use of HRT in any manner that's not respectful of the downside," said Dr. Freya Schnabel, director of breast surgery at NYU Langone Medical Center in New York City. "The WHI had returned hormone therapy to the realm of medicine, not jelly beans. It's medication that has to be viewed in the exact same context of risks and benefits, indications and contraindications. There is a real downside to taking HRT, and getting breast cancer is not a trivial matter at all."
U.S. National Heart, Lung,
and Blood Institute for more on the Women's Health
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