Cervical cancer risk link to contraceptive pill

Women who take the contraceptive pill may increase their risk of cervical cancer, according to a major new study published in the Lancet today.

A team of scientists from Cancer Research UK and the International Agency for Research on Cancer conducted an extensive review of research on oral contraceptive use and cervical cancer risk – involving data from 24 countries.

Researchers found that the longer women used the pill the greater their risk of developing cervical cancer. The effect remained even when other risk factors for the disease such as infection with the Human Papilloma Virus (HPV) were taken into account.

Cancer Research UK experts stress that further research is needed to determine whether the risk of cervical cancer drops after women stop using the pill, before implications for public health can be fully understood. They also emphasise the importance of regular cervical screening for all women, whether or not they use the pill.

Persistent infection with some types of sexually transmitted HPVs is thought to be the most important cause of cervical cancer. But whether women infected with HPV go on to develop cervical cancer may be affected by other factors such as the use of hormonal contraceptives. Some previous studies had suggested a link between cervical cancer and the pill but the evidence had been unclear.

In the study, commissioned by the World Health Organisation, researchers combined the data from 28 studies, involving 12,500 women with cervical cancer from a number of countries including the UK and USA.

They found that women who used the pill for five years or less had a 10 per cent increased risk of cervical cancer when compared with women who had never taken it. This increased risk rose to 60 per cent with five to nine years of use and doubled with 10 years of use or over.

A similar pattern of increased risk was seen when researchers took into account other factors which could influence cervical cancer risk, such as whether the women smoked, their number of sexual partners, whether they had previously attended cervical cancer screening and whether they used barrier methods of contraception.

(GMcG)