CHICAGO (AP) - The first follow-up of a landmark
study of hormone use after menopause shows heart
problems linked with the pills seem to fade after
women stop taking them, while surprising new cancer
risks appear.
That heart trouble associated with hormones may not
be permanent is good news for millions of women who
quit taking them after the government study was
halted six years ago because of heart risks and
breast cancer.
But the new risks for other cancers, particularly
lung tumors, in women who'd taken estrogen-progestin
pills for about five years puzzled the researchers
and outside experts.
Those risks "were completely unanticipated," said
Dr. Gerardo Heiss of the University of North
Carolina in Chapel Hill, lead author of the
follow-up analysis.
The analysis focused on participants' health in the
first two to three years after the study's end.
During that time, those who'd taken hormones but
stopped were 24 percent more likely to develop any
kind of cancer than women who'd taken dummy pills
during the study.
"There's still a lot of uncertainty about the cause
of the increased cancer risk," said analysis
co-author Dr. JoAnn Manson, chief of preventive
medicine at Harvard's Brigham and Women's Hospital.
The cancers included breast tumors, which also
occurred more frequently in hormone users during the
study.
The researchers noted that the increased risks for
all cancers amounted to only three extra cases per
year for every 1,000 women on hormone pills,
compared with nonusers.
Still, Heiss said the results suggest that former
hormone users need to be vigilant about getting
cancer screening including mammograms.
"Vigilance is justified," he said. "No alarm, but
vigilance."
The initial study of 16,608 postmenopausal women was
designed to examine pros and cons of taking pills
long thought to benefit women's health. It was
halted in 2002 when more breast cancers, heart
attacks and related problems were found in hormone
users versus nonusers.
There were some health benefits - decreased risks
for hip fractures and colorectal cancer - but the
follow-up found those also faded after women stopped
the pills.
Some data suggest that U.S. breast cancer rates have
declined since the study's end. But that likely
reflects fewer women starting on the pills rather
than any decline in breast cancer risk among past
users, said Dr. Michael Lauer of the National Heart,
Lung and Blood Institute at the National Institutes
of Health, which conducted and funded the landmark
research.
The authors said the new results send the same
message they've been advocating ever since the study
ended: Health risks from estrogen-progestin pills
outweigh their benefits, and they should only be
used to relieve hot flashes and other menopause
symptoms, in the lowest possible dose for the
shortest possible duration.
The new analysis appears in Wednesday's Journal of
the American Medical Association.
A spokesman for Wyeth Pharmaceuticals, maker of the
Prempro estrogen-protestin pills used in the study,
voiced a criticism frequently cited by scientists,
too - that participants were in their 60s on
average, at least 10 years older than typical
hormone users. The latest results thus may not apply
to typical users because older women have different
health risks than younger ones, including more
cancers in general, said Wyeth's Dr. Joseph Camardo.
Prempro's packaging information already recommends
routine breast exams and mammograms for users, and
Camardo said the follow-up results are "not anything
that's particularly new that should change
guidance."
Manson, the co-author, said it's possible the
initial study results prompted hormone-using
participants to see their doctors more often than
nonusers after the study ended, which could have
resulted in more cancers detected.
It's also possible hormones either triggered new
tumors or fueled the growth of existing ones, the
researchers said.
"Once a tumor gets started, you might think of it as
a train is out of the station and it might be more
difficult to stop it," Lauer s:
JAMA: http://jama.ama-assn.org
Hormone study: http://www.nhlbi.nih.gov/whi/estro-pro.htm
