25th August 18:03
Hormone Pills May Spur Breast Cancer (dementia menopause heart cancer estrogen)
Hormone Pills May Spur Breast Cancer
Wed Jun 25, 1:09 PM ET
Add Health - AP to My Yahoo!
By LINDSEY TANNER, AP Medical Writer
CHICAGO - More negative fallout from a landmark government study
suggests breast cancer (news - web sites) linked to estrogen-progestin
pills may be fast-growing and hard to detect, clarifying risks for
millions of women still using hormone treatment.
"Hopefully, it will convince women to reconsider," said Dr. Susan
Hendrix of Wayne State University in Detroit, a co-author of the new
****ysis. "We've got to find a better way to help women with their
Some previous studies suggested breast tumors might be less aggressive
in hormone users; other studies indicated the opposite. Previous
research also suggested that hormones might make breast tissue more
dense, hindering the detection of tumors.
Seeking more definitive answers, the researchers took a closer look at
data from the government's landmark Women's Health Initiative study,
which was halted last summer after it was found that
estrogen-progestin pills raise the risk of heart attack, strokes and
While last summer's findings led many women to stop taking hormones,
Hendrix said an estimated 3 million women still use them, primarily to
relieve hot flashes and other symptoms of menopause.
The latest findings appear in Wednesday's Journal of the American
Medical Association (news - web sites).
The ****ysis involved 16,608 women ages 50 to 79 who used either
combined hormone treatment or dummy pills for an average of five
As of January, breast cancer had developed in 245 women who used the
combined hormone treatment and in 185 women who had taken dummy pills.
Hormone users' tumors were larger at diagnosis, 1.7 centimeters on
average versus 1.5 centimeters in placebo women. Tumors had begun to
25.4 percent of hormone users, compared with 16 percent of placebo
The researchers said this appears to mean that in women on
estrogen-progestin, the tumors both grow faster — that is, they are
more aggressive — and escape detection longer.
Overall, women on both hormones faced a 24 percent increased risk of
breast cancer — equal to eight extra cases of cancer per year for
10,000 women taking the pills.
The increased risk did not appear in the first two years of treatment.
But Hendrix said the tumors may have been present early on but were
not detected until later because of hormone-induced breast density.
The new ****ysis did not examine breast density. But researchers think
progestin may be the culprit because it can cause breast cells — both
normal and abnormal — to proliferate, an effect that may be
accentuated when the hormone is combined with estrogen.
Wyeth Pharmaceuticals, maker of the Prempro pills used in the study,
said hormones remain an appropriate therapy when used at the lowest
possible dose for the shortest possible time.
The latest ****ysis is by far the most conclusive, said Dr. Peter
Gann, an associate professor of preventive medicine at Northwestern
University who was not involved in the study.
It "further worsens the news for long-term hormone replacement
therapy. It suggests the excess breast cancer risk is not trivial,"
Last summer's Women's Health Initiative findings shattered long-held
beliefs that hormones are good for women's hearts. Last month, another
****ysis of data from the study found that instead of sharpening the
mind, hormones may double the risk of Alzheimer's and other forms of
A second, smaller study in Wednesday's journal also confirmed a link
between combined hormone treatments and breast cancer and suggested
estrogen-only treatment may be safer.
The study involved 975 Seattle-area women ages 65 to 79. The greatest
breast cancer risk was in women who used estrogen-progestin for at
least five years, even if they took the progestin component only some
days a month.
Those who used estrogen alone, even for 25 years or longer, showed no
appreciable increased risk, according to the study, led by Dr.
Christopher Li of Fred Hutchinson Cancer Research Center in Seattle.
Estrogen alone is recommended only for women with hysterectomies
because it can cause uterine cancer unless balanced by progestin.
The researchers said more definitive answers will come from the
continuing estrogen-only part of the Women's Health Initiative study.