We don’t know what causes all vulval cancers. But there are some risk factors that can increase your risk of developing it. These include being older and having infections with certain viruses.
Anything that can increase your risk of getting a disease is called a risk factor.
Different cancers have different risk factors. Having one or more of these risk factors doesn't mean you will definitely get that cancer.
As with most cancers, vulval cancer is more common as you get older. On average each year more than 40 out of 100 (more than 40%) new cases are in women aged 75 and over.
Vulval cancers can also occur in young women but this is rare.
Human papilloma virus (HPV) infection
The human papilloma virus (HPV) can infect the skin in different parts of the body, including the vulva. HPV can pass from one person to another by skin to skin contact, usually during sexual activity including oral sex.
Researchers think that around 80 out of 100 people will be infected with HPV at some time during their lives. So it is a very common infection. In most people, it doesn't cause any problems and goes away without treatment. But people infected with high risk HPV types are more likely to go on to develop cancer, including vulval cancer.
Almost 70 out of every 100 vulval cancers are caused by HPV infections.
There are many different types of HPV and some are more likely to cause vulval cancer than others. The most common types of HPV related to vulval cancer are:
- HPV type 16
- HPV type 33
- HPV type 18
The HPV vaccine helps to protect against HPV infections. All children aged between 11 and 13 in the UK can get the HPV vaccine. It is also offered to some people in older age groups too.
Weakened immune system
Your risk of developing vulval cancer is higher if you have a weakened
HIV is the virus that causes AIDS (acquired immune deficiency syndrome). This virus weakens your immune system and so you are more likely to pick up other infections, such as HPV.
The risk is also higher in people who have had an organ transplant. This is because you have to take drugs to suppress your immune system after a transplant. This is to stop the body from rejecting the transplanted organ.
Lichen sclerosus is a long term vulval skin condition that causes itching and sometimes pain in the vulval area. This usually affects women over the age of 60. Women with lichen sclerosus may develop a condition called differentiated vulval intraepithelial neoplasia (dVIN).
Without treatment, dVIN can turn into vulval cancer.
Vulval intraepithelial neoplasia (VIN)
VIN is a skin condition of the vulva. It means that abnormal cells have developed in the surface layers of the skin covering the vulva. It is not cancer but could turn into vulval cancer. This may take many years.
Some studies have shown that having had other types of cancer can also increase the risk of vulval cancer. This includes:
- cervical cancer
- pre cancerous changes in the cells of the cervix (CIN)
This is because both cancers have similar risk factors such as HPV.
Other possible causes
Stories about potential causes are often in the media and it isn’t always clear which ideas are supported by evidence. There might be things you have heard of that we haven’t included here. This is because either there is no evidence about them or it is less clear.
Reducing your risk
There are ways you can reduce your risk of cancer.