The contraceptive Pill
High levels of our own natural hormones can increase our risk of some cancers, such as breast and womb cancers. Some medical treatments, including hormone replacement therapy (HRT) and the contraceptive Pill, work by increasing levels of certain hormones. So scientists have investigated whether using them could affect the risk of developing cancer.
This page will talk about the Pill and how it affects your cancer risk.
Different types of Pill
Oral contraceptives, commonly known as ‘the Pill’, are a popular form of birth control in the UK. There are two main types:
- The combined Pill. This is by far the most common type and consists of two female sex hormones - oestrogen and progestogen.
- The mini-Pill. This pill only contains progestogen. It’s also known as the progestogen-only Pill or POP.
The combined Pill and cancer
Scientists have found that the combined Pill:
The longer a woman takes the combined Pill for, the higher her risk of cervical cancer while she is taking it. Taking it for only a short time may not have any noticeable effect, but women who have been using it for 5 years or more have nearly double the risk of developing cervical cancer compared to women who have never used the combined Pill. However, the risk starts to fall back down again once a woman stops using it. About 10 years after stopping, her risk is no longer affected.
Almost all cases of cervical cancer are caused by human papillomavirus (HPV). Other things like smoking or taking the Pill, can further increase the risk of cervical cancer. It’s not yet clear how the Pill might do that, though there a number of possibilities. For example, the Pill might stop the body from clearing HPV infection. More research is needed to work out what’s going on.
The combined Pill also slightly increases a woman’s risk of breast cancer. In the UK, about 1% of breast cancers in women are caused by oral contraceptives. The higher risk starts to drop once a woman stops taking the Pill, and disappears by 10 years.
The pill can protect against some cancers
But the combined Pill also offers some protection against certain cancers. It reduces a woman’s risk of ovarian and womb cancers. These protective effects are bigger the longer she takes the combined Pill for and continue for decades after she stops taking it. And there is some evidence the pill may reduce the risk of bowel cancer.
The mini-Pill (progestogen-only Pill, POP) and cancer
Because fewer women use the mini-Pill, it’s harder for scientists to investigate enough women to be sure any effect on cancer risk they see isn’t down to chance. Based on a small number of studies, it looks as if the mini-Pill affects a woman’s risk of cancer in the same way as the combined Pill. But we can’t say this for sure until larger studies are done.
Should I use the Pill?
The protective effects of the Pill against womb and ovarian cancers last longer than the increased risks of breast and cervical cancers. Overall, this means that the protective effects outweigh the increased risk of cancer if you look at all women who have taken the Pill. But even though on average the level of protection is bigger than the extra risk, so the chances are you’ll benefit, some individual women will develop cervical or breast cancer because they have used the Pill.
Your doctor can help you to make an informed choice about whether to use the Pill. This decision should weigh up the risks and benefits, your lifestyle, any other medical conditions, your personal preferences, and whether you have a strong family history of cancer.