Risks and causes of ovarian cancer
Ovarian cancer can affect anyone born with female reproductive organs including the ovaries and fallopian tubes. This includes women, transgender men and non-binary people.
We don’t know what causes most ovarian cancers. But there are some risks factors that can increase your risk of developing it. These include being older or being overweight.
Anything that can increase your risk of getting a disease is called a risk factor. Anything that lowers the risk are called protective factors.
Different cancers have different risk factors. Having one or more of these risk factors doesn't mean you will definitely get that cancer.
Getting older
As with most cancers, ovarian cancer becomes more common as you get older. The risk of ovarian cancer increases steeply from around 45 years. And is greatest in those aged between 75 and 79 years.
Inherited faulty genes and family history
Some people have a higher risk of developing ovarian cancer because other members of their family have had it. This is called a family history of cancer. For example, having a 
diagnosed with ovarian cancer increases the risk of ovarian cancer.
Some people have an increased risk of ovarian cancer because they have an inherited gene change (fault). Several gene faults or genetic conditions can increase ovarian cancer risk. This includes a fault in the:
- BRCA 1 or BRCA 2 gene
- RAD51C or RAD51D gene
- BRIP1 gene
- PALB2 gene
Having one of these faulty genes means that you are more likely to get ovarian cancer than someone who doesn’t. But it is not a certainty.
Having certain genetic conditions (syndromes) can increase the risk of ovarian cancer and some other cancers. These include:
- Lynch syndrome
- Peutz-Jeghers syndrome
If you are worried about your family history of ovarian cancer, speak to your GP. They can tell you whether you might benefit from a referral to a genetics service.
Being overweight or obese
Being overweight or obese increases your risk of getting ovarian cancer. And the more overweight you are, the higher your risk. But this doesn’t mean that you will definitely develop cancer. There is information and support available to help keep you healthy. This includes being active and eating a healthy diet.
Medical conditions
Studies have shown that women with or diabetes have an increased risk of ovarian cancer.
Hormone replacement therapy (HRT)
Using HRT to reduce symptoms of menopause slightly increases the risk of ovarian cancer. The risk depends on many different things including the type of HRT used, how long someone takes it for, their age, and general health.
Remember that the increase in risk is small and HRT is helpful for many people with menopausal symptoms. Talk to your GP about the risks and benefits of taking HRT in your situation.
Smoking
Smoking can increase the risk of certain types of ovarian cancer such as mucinous ovarian cancer. The longer you have smoked, the greater the risk.
Asbestos
Asbestos is an insulating material that’s heat and fire resistant. It was used in shipbuilding and the construction industry in the 1960s.The use of asbestos was banned in the late 1990s in the UK.
Asbestos is made up of tiny fibres. You can breathe these fibres in when you come into contact with asbestos. There are strict laws about work that involves asbestos.
The International Agency for Research on Cancer (IARC) classify asbestos as a cause of ovarian cancer.
Possible protective factors
The following factors may reduce your risk of ovarian cancer:
Taking the combined contraceptive pill
Taking the combined contraceptive pill reduces your risk of ovarian cancer. Research has shown that the longer you take the pill, the more your risk is reduced. The reduction in risk lasts for at least 30 years after you stop taking the pill, though this reduction may become less over time.
Having children and breastfeeding
Having children seems to reduce the risk of ovarian cancer. The more children you have, the lower the risk. Breastfeeding also reduces the risk of ovarian cancer.
This reduction in risk may be because while you are pregnant or breastfeeding you're not ovulating (releasing eggs). The fewer times you ovulate in your lifetime, the lower the risk of ovarian cancer.
Are there other causes?
Stories about possible cancer causes are often in the media and it can be hard to know what’s true and what’s not. You may have heard of something that isn’t included here. This is because we only include a risk factor in this information if it is supported by good quality evidence.
More information on ovarian cancer risks and causes
We have more detailed information for health professionals about ovarian cancer risks and causes.
