HRT treatment raises risk of ovarian cancer, says study

Women who undergo hormone
replacement therapy (HRT) have a
significantly increased risk of developing
ovarian cancer, according to a major study.
Researchers from the University of Oxford
analysed 52 previous studies involving
21,000 women and found that even those
who took it for less than five years raised
the risk level, although it reduced once
they had stopped.
With researchers estimating 1 million
women in Britain use HRT to relieve
symptoms of the menopause, the study’s
co-author, Sir Richard Peto, told the BBC
the link could affect hundreds of women
each year.
The study, published in the Lancet
medical journal, has led to calls for
medical guidance on HRT to be updated
given the “causal relationship” and the
Medical and Healthcare Products
Regulatory Authority (MHRA) said it would
look at the findings.
The researchers said: “The increased risk
may well be largely or wholly causal; if it
is, women who use hormone therapy for
five years from around age 50 have about
one extra ovarian cancer per 1,000 users
and, if its prognosis is typical, about one
extra ovarian cancer death per 1,700 users.
“The findings that ovarian cancer risk is
greatest in current users of hormone
therapy, falls after use ceases, and varies
by tumour type, strongly suggest a causal
relationship – ie, that among otherwise
similar women, use of hormone therapy
increases the probability of developing the
two most common types of ovarian cancer,
and hence ovarian cancer as a whole.
“At present, the WHO [World Health
Organisation], European, and US
guidelines about hormone therapy do not
mention ovarian cancer, and the UK
guidelines – which are due to be revised –
state only that risk may be increased with
long-term use.
“The definite risk of ovarian cancer that is
observed even with less than five years of
use starting at around age 50 is directly
relevant to current patterns of hormone
therapy use, and hence directly relevant to
medical advice, personal choices, and the
current efforts to revise UK and worldwide
Dr Sarah Branch, deputy director of
MHRA’s Vigilance and Risk Management of
Medicines (VRMM) division, said: “Our
advice has always been that the lowest
effective dose of HRT should be used for
the shortest possible time.
“We will evaluate the findings of this
study and its implications for shorter term
use and update product information as
“Women on HRT should have regular
health checkups and their need to continue
treatment should be reassessed at least
annually. Any woman on HRT who has any
questions should speak to her doctor who
is best placed to advise.”