Contraceptive pill does not increase cancer risk
Taking oral contraceptive pills for less that eight years does not increase a woman's chances of developing cancer and may reduce the risk for many, a new study has found.
Researchers from the University of Aberdeen analysed 36 years' worth of data from the Royal College of General Practitioners' (RCGP) Oral Contraception Study.
Around half of the 46,000 participating women had taken oral contraceptives at some stage, while the remainder had never taken the Pill.
Information on the women's health, provided every six months by their GP, suggested that women who had taken the Pill had a three per cent reduced risk of developing cancer.
The researchers also obtained information on three quarters of the women from the NHS central registries, enabling them to get information on cancer and mortality for women who had changed GP.
Using this latter data, the researchers found that women who had taken oral contraceptives had a 12 per cent reduction in cancer risk, equal to one less case of the disease for every 2,200 women who had used the Pill for one year.
Women who had taken the Pill had lower rates of bowel, rectal, womb and ovarian cancer and the protective effect appeared to last for at least 15 years after stopping oral contraception.
However, the researchers noted that women who had taken the Pill for longer than eight years had a slightly increased risk of developing cancer, particularly cervical and brain cancer, although they still had a reduced risk of ovarian cancer.
Publishing their findings online in the British Medical Journal, the researchers, led by Professor Philip Hannaford of the University of Aberdeen's Department of General Practice and Primary Care, revealed: "In this UK cohort, oral contraception was not associated with an overall increased risk of any cancer, indeed it may even produce a net public health gain."
Dr Julie Sharp, science information manager at Cancer Research UK, pointed out that we have long known that oral contraceptives temporarily increase the risk of some cancers while reducing the risks of others.
"This study looks at the long-term effects of taking the Pill and it suggests that users are at no greater risk of cancer over their lifetime than non-users," she said. "It remains important for women to be aware of the short-term risks of using the Pill, such as an increased risk of breast and cervical cancer, but this research suggests that these risks may be balanced out by health benefits over the longer term," she added.