Oral Contraceptive Use For Fewer Than Eight Years Reduces Cancer Risk

Armen Hareyan's picture

Oral Contraceptive

Women's use of oral contraceptives for fewer than eight yearsreduces overall cancer risk by up to 12%, but use of contraceptives formore than eight years increases cancer risk by 22%, according to astudy published on Tuesday in the British Medical Journal, London's Times reports (Hawkes, Times, 9/12).

For the study, Philip Hannaford of the University of Aberdeen and colleagues studied the records from the Royal College of General Practitionersof 46,000 women -- about half of whom began using oral contraceptivesin 1968 -- over a 36-year period in the United Kingdom. About half ofthe women in the study never used oral contraceptives, Reuters reports (Reuters, 9/12). According to the Scotsman, researchers accounted for factors such as age, smoking and social class (Moss, Scotsman, 9/12).

General practitioners provided researchers with information on the women's health every six months, according to a BMJ release.Researchers analyzed two sets of data -- one that included recordedcancers among women who remained with their original generalpractitioner and another that also included cancers recorded in National Health Serviceregistries after women left their original physicians. Aboutthree-quarters of the women in the study were included in the NHSregistries (BMJ release, 9/11).


Using the datareported to general practitioners and NHS, which included cancersrecorded until 2004, researchers found that women who took oralcontraceptives for eight years or less had a 12% reduction in overallcancer risk, which equates to one fewer case of cancer a year for every2,200 women who used oral contraceptives. Among the approximatelyone-quarter of contraceptive users who took the drugs for more thaneight years, the risk of overall cancer increased by 22%, the studyfound. Using the smaller set of data, which included information fromgeneral practitioners up to 1996, researchers found that contraceptiveuse reduced cancer risk by 3% (Times, 9/12).

The study found no evidence of decreased or increased risk of breast cancer among short-term contraceptive users (Times,9/12). Statistically significant reduced risks of large bowel, ovarianand uterine cancer were evident among contraceptive users, BBC News reports.Evidence also suggest that women who took oral contraceptives wereprotected from the risk of developing cancers for at least 15 yearsafter they stopped using the drugs (BBC News, 9/11).


Hannaford said, "My message for women is that if you want to use thepill for contraceptive reasons, then go ahead. It will not increaseyour lifetime risk of developing cancer." He added that if women "wantto use it for longer than eight years, then the risk increases slightlybut that does not mean they have to stop using it."

Maria Leadbeater, a nurse specialist at Breast Cancer Care,said the findings would be welcomed by the thousands of women in theUnited Kingdom. She added, "From talking to women on our helpline, weknow the anxiety that concerns over the pill can cause. This researchwill be a great reassurance to them." Toni Belfield of the Family Planning Association said the "study further confirms that for the majority the benefits [of oral contraceptives] far outweigh any risks" (Moss, Scotsman, 9/12).

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