News Release

Transient increase in cervical cancer risk in oral contraceptive users

Peer-Reviewed Publication

The Lancet_DELETED

Current users of oral contraceptives are at increased risk of developing cervical cancer, however 10 years after stopping use the risk returns to that seen for never-users. These are the conclusions of authors of an Article published in this week's edition of The Lancet.

Dr Jane Green, Cancer Epidemiology Unit, University of Oxford, UK and colleagues from the International Collaboration of Epidemiological Studies of Cervical Cancer pooled and re-analysed data from 24 studies worldwide, which included over 16000 women with cervical cancer and over 35000 without.

The study confirms previous evidence that among current users of oral contraceptives, the risk of invasive cervical cancer increases with increasing duration of use -- with those who have used contraceptives for five years or more having about twice the risk compared with never users. This study shows for the first time how long this effect persists after oral contraceptive use stops. A similar pattern of risk was seen both for invasive and in-situ cancer, and in women who tested positive for the high-risk type of human papillomavirus which causes cervical cancer.

The authors point out: "The incidence of cervical cancer increases with age and so the contribution of hormonal contraceptives to the lifetime incidence of cervical cancer will depend largely on the effects at older ages, when most women are past users." Further, they estimate that 10 years use of oral contraceptives from around age 20 to 30 years increases the cumulative incidence of invasive cervical cancer by age 50 from 3.8 to 4.5 per 1000 women in more developed countries, and from 7.3 to 8.3 per 1000 women in less developed countries.

The authors explain (note this quote is not in the paper): "However, these results need to be seen in context -- in the long term the extra risk of cervical cancer in oral contraceptive users is more than outweighed by a reduction in risk of ovarian and endometrial cancers."

In an accompanying Comment, Dr Peter Sasieni, Wolfson Institute of Preventive Medicine, Queen Mary University of London, UK, says that the study will lead to greater understanding of the cofactors affecting cervical cancer, and that the results (showing a small increase in absolute risk) should "reassure women that fear of cervical cancer should not be a reason to avoid use of oral contraception."

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For Dr Jane Green, please contact Paul Thorne, Science and Health Press Office, Cancer Research UK, T) +44 20 7061 8300 E) Paul.Thorne@cancer.org.uk

Dr Peter Sasieni, Wolfson Institute of Preventive Medicine, Queen Mary University of London, UK T) +44 20 7014 0260 E) peter.sasieni@cancer.org.uk

The paper associated with the press release is listed below:
http://multimedia.thelancet.com/pdf/press/CervicalCancer.pdf


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