Can being on the pill cause cancer? Does the risk last even if you've stopped taking it?
A large analysis of most of the studies carried out worldwide into oral contraceptives (the pill) and the risk of breast cancer, showed that women using the pill have a slight but significant increase in breast cancer risk. But the evidence suggests that the risk starts to drop once you stop taking the pill and 10 years after you stop your risk of breast cancer is back to normal.
If you have a family history of breast cancer, you may feel that this increase in risk (however small it is) is not worth taking. Doctors don't think that pill use is likely to change the size of the risk in women who have close relatives with breast cancer. But we don't really have the research evidence to say how pill use might affect breast cancer risk in those with a family history.
If you have a history of breast problems, such as benign lumps, you may also feel that you should be extra cautious. It is thought that the oestrogen in the combined pill may cause the increased risk. So it may be better to take a brand of pill that has lower oestrogen. In the UK, most women are automatically put onto a low oestrogen combined pill by their doctors.
There has been some research indicating that using the pill increases the risk of cancer of the cervix. The picture is confusing because women who take oral contraceptives are more likely to be sexually active. And may not necessarily use barrier contraception (condom), so they are more at risk of picking up HPV, which is a known risk factor for cervical cancer.
Overall, the research suggests that even taking these factors into account, the use of oral contraceptives is independently linked to an increased risk of cervical cancer. The risk starts to drop as soon as you stop taking it. After 10 years the risk is the same as if you had never taken it.
There is more information about the risks and causes of cervical cancer in the cervical cancer section.
The combined contraceptive pill protects you against ovarian cancer. This is particularly important if you have ovarian cancer in your family. The protection comes from the pill suppressing hormones that naturally stimulate the ovaries. It seems that the longer you take the pill, the lower your risk of ovarian cancer.
There is more information about the risks and causes of ovarian cancer in the ovarian cancer section.
The combined pill also protects against cancer of the womb. It is probably the progesterone that helps here, rather than the oestrogen. Research suggests that protection against womb cancer lasts for at least 15 years after you stop taking the pill.
A study published in 2007 shows that the pill may also protect against bowel cancer. Overall, the research evidence suggests that women who have taken the pill have about a 20% lower risk of bowel cancer. But we need more research to be sure.