Birth control pills may protect against some cancers

Women who take the contraceptive pill are not putting themselves at a higher risk of cancer. Research by the University of Aberdeen suggests that the pill can actually protect women against some types of cancers.
From an analysis of more than 46,000 women, researchers from the University of Aberdeen in the United Kingdom found that women who had ever used oral contraceptive pills were at lower risk of colorectal, ovarian, and endometrial cancers, compared with women who had never used the pill.
Furthermore, the study found no link between the use of oral contraceptives during reproductive years and increased risk of new cancers in later life.
Long-Term Investigation
The findings are the latest to emerge from the Oral Contraception Study which was established in 1968 by the Royal College of General Practitioners (RCGP) to investigate the long-term effects of the oral contraceptive pill. 
At the start of the study, the pill was still a relatively new type of contraception, having first been introduced in the US in 1960. 
Concerns were expressed early on about whether the pill could cause cancer. These concerns, together with media scares, have led generations of women to question the possible risks to their health from choosing this method of birth control.
Cancer Concerns
A number of studies have examined a potential link between the pill and different types of cancer. The results collectively suggested that women who are or have been recently on the pill have an increased risk of breast and cervical cancer. On the other hand, oral contraceptive users seemed to have a reduced risk of endometrial and ovarian cancers. 
Also, current pill users seemed to be protected from bowel cancer, although it remained inconclusive whether this protection persisted after pill use came to an end. 
For the UK study, 46,022 women were recruited and their health followed for up to 44 years. This makes it the world's longest-running study into the effects of the pill. 
An analysis of the data, published in the American Journal of Obstetrics and Gynaecology, found that taking the pill led to:
· A 19% lower risk of bowel cancer
· A 34% lower risk of endometrial cancer
· A 33% lower risk of ovarian cancer
Also, these protective effects have been shown to last for at least 30 years after pill use ended.

Reassurance
The researchers also examined the risk of all types of cancer in women who have taken the pill. This showed that using the pill during reproductive years does not produce new cancer risks for women later in life, when cancers become more common in the population as a whole.
Commenting on the results in a statement, Professor Helen Stokes-Lampard, chair of the RCGP, says: "Millions of women worldwide who use the combined oral contraceptive pill should be reassured by this comprehensive research that they are not at increased risk of cancer as a result – and that taking the pill might actually decrease their risk of certain cancers."
However, she adds: "This is not to advocate that women should be given the pill as a preventative measure against cancer as we know that a minority of women do have adverse health effects as a result of taking the pill. Ultimately decisions to prescribe the pill need to be made on a patient by patient basis, but this research will be useful to inform the conversations we have with our patients when discussing various contraceptive options that are available."
Lifetime cancer risk and combined oral contraceptives: the Royal College of General Practitioners' Oral Contraception Study, Iversen L et al, the American Journal of Obstetrics and Gynaecology
University of Aberdeen
Royal College of General Practitioners (RCGP)

Original article published at medscape.com