- LONDON (Reuters Health) -
Long-term use of oral contraceptives increases the risk of cancer of the
cervix up to fourfold in women infected with the human papillomavirus
(HPV),
according to study findings released by The Lancet on Tuesday.
-
- HPV is a common sexually transmitted infection that often
goes away on its own. But infection with certain HPV strains is linked
to an increased risk of cervical cancer.
-
- Researchers at the World Health Organisation's
International
Agency for Research on Cancer pooled data from 10 studies involving
patients
with cervical cancer and healthy "control" patients. The journal
lifted its normal publication embargo after reports of the study results
appeared in British newspapers.
-
- The analysis of eight case-control studies included 1,676
women with cancer and 255 controls, all of whom were infected with HPV.
Results were adjusted for education, indicators of sexual activity and
screening history as well as age and geographic location.
-
- The investigators found no increased risk of cervical
cancer in women who had used oral contraceptives for less than 5 years
compared with women who had never taken oral contraceptives.
-
- But women who had taken the Pill for 5 to 9 years were
nearly three times more likely to develop cervical cancer, while those
who used oral contraceptives for 10 years or longer had a more than
fourfold
increased cancer risk, Dr. Victor Moreno from the Catalan Institute for
Oncology in Barcelona, Spain, and colleagues report.
-
- "Long-term use of oral contraceptives could be a
cofactor that increases the risk of cervical carcinoma by up to fourfold
in women who are positive for cervical HPV DNA," they state.
-
- Timothy Farley, of the department of reproductive health
and research at the World Health Organisation (WHO) in Geneva, said the
new research helped clarify the different risks involved in cervical
cancer.
-
- "We've known for some time that women who take the
Pill have a greater risk of developing cervical cancer. We haven't been
sure if it's the effect of the Pill or the effect of people's behaviour.
Women who have a high number of sexual partners have a high risk of
cancer,"
he told Reuters Health.
-
- "We don't know for sure if it is behavioural or
not but that seems less likely than before. It may be an effect of the
Pill," he said.
-
- "Our results could help women who have persistent
HPV infection to balance benefits--such as prevention of pregnancy and
cancers of the ovary--and harms of long-term oral contraceptive use, and
suggest that long-term users of oral contraceptives should be included
in cervical screening programmes."
-
- Farley noted, "It is very important to realise that
the risk of developing cervical cancer is very small. The majority of women
who develop cervical cancer have never even seen (an oral contraceptive
pill). There is no reason for women to change the use of the Pill because
of the results of this study."
-
- He added, "People should not decide against using
the Pill because of concerns about cervical cancer. It's a risk, but a
small risk. The benefits of the Pill in terms of quality of life and
preventing
unwanted pregnancies far outweigh that risk."
-
- SOURCE: The Lancet online
2002 March 27.
-
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