Hormone
replacement therapy has been classed as cancer-causing by
the World Health Organization's cancer agency.
The combined
menopause therapy was previously said to be "possibly" cancer
causing, but the agency said women should not automatically
stop using it.
The scientists also warned the combined contraceptive pill slightly
increased the risk of a greater number of cancers than originally
thought.
UK experts said the HRT findings did not add anything to what
is known.
A group of 21 scientists from the International Agency for Research
on Cancer reviewed published evidence on both drugs before coming
to their conclusions.
"It's
a complicated picture" --- Vincent Cogliano,
of the International Agency for Research on Cancer
On combined
estrogen-progestogen HRT, they said studies had demonstrated
an increased risk of breast cancer. The risk exceeded with duration
of use.
And they said use of the combined estrogen-progestogen contraceptive
pill slightly increased the risk of breast, cervix and liver
cancer. Past studies have already linked the pill to liver cancer,
but only in hepatitis B-endemic countries.
But the scientists said it decreased the risk of endometrial
and ovarian cancer.
'Complicated'
Agency official Vincent Cogliano said: "It's a complicated picture.
It doesn't mean women should stop taking the treatment. There
are still other reasons to take it.
"Each woman has to discuss it with her doctor and with the risks
and benefits."
Dr Anne Szarewski, clinical consultant for Cancer Research UK,
said: "We are unaware of any studies that have shown that the
contraceptive pill causes breast or cervical cancer.
"Studies have only shown that there is an association.
"Regarding HRT, this statement does not add anything to the
information that has already been published in recent studies."
UK drugs regulator, the Medicines and Healthcare products Regulatory
Agency, said the warnings added nothing to what was already
known.
Hormone
replacement therapy has been classed as cancer-causing by
the World Health Organization's cancer agency.
