LONDON (Reuters) - A British
study backed US findings on the side-effects of hormone replacement
therapy (HRT) on Friday, saying the treatment taken by women to
relieve menopause symptoms increases the risk of breast cancer
A review of four major studies into the effects of HRT found that
women who took the treatment for five years had a higher risk of
breast cancer, stroke and blood clots in the lung but were less
likely to suffer from bowel cancer or hip fractures.
Overall, the analysis
showed that a woman is more likely to contract a life-threatening
disease when on HRT than to be protected against one.
"The four major trials
that have been done, although in different settings and with different
combinations (of HRT), really show consistent results," Professor
Valerie Beral, of Britain's Cancer Research UK charity, told Reuters.
Millions of women who
use HRT to relieve hot flushes and mood swings or to prevent osteoporosis
were caught off guard in July after an American trial showed HRT
raises the risk of stroke, breast cancer and blood clots.
Shares in HRT manufacturers
like US-based Wyeth and Germany's Schering tumbled in the wake
of the US trial news in July.
US FINDINGS BACKED
Beral said her analysis
of four trials involving 20,000 postmenopausal women, which is
published in The Lancet medical journal, confirm the findings
of the US study.
"They basically support
the Women's Health Initiative study," Beral said, referring to
the US trial of women taking combined estrogen and progestogen
Three of the trials in
the analysis studied the effects of combined HRT and one involved
"Putting all the data
together, the results look very similar," said Beral. "What there
is suggests there is no difference between the different types
of HRT preparations."
For women in their 50s
taking HRT for five years, the greatest risk is for developing
breast cancer. Women in their 60s have a higher chance of suffering
a stroke or pulmonary embolism, or blood clots in the lungs.
"These result estimates
provide a rough guide to the likely overall change in incidence
of these conditions over a five-year period for typically healthy
women in Western countries who use HRT," said Beral.
The review estimates
that for healthy women on HRT for five years there would be a
total of six extra cases of either breast cancer, stroke or clot
on the lung among every 1,000 HRT users between aged 50-59.
The number would double
to 12 for HRT users aged 60-69.
By contrast, there would
be an estimated 1.7 fewer cases of bowel cancer or hip fracture
per 1,000 HRT users aged 50-59 and 5.5 per 1,000 users between
The review found no significant
change in the risks of endometrial cancer or coronary heart disease.
Women on the treatment
for longer would have an increase in risk that accumulates with
time, said Beral
"We've tried to provide
risk estimates for women that they can relate to in making a decision
about whether they want to take HRT or not," she added.
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