Risk factors of vulval cancer

The cause of vulval cancer is unknown, but there are some risk factors that can increase a woman’s chance of developing it:

  • Age – most of the women who are diagnosed with vulval cancer are aged 65 and over, but it can affect younger women.
  • Vulval skin conditions – women with non-cancerous vulval skin conditions such as lichen sclerosus, lichen planus and Paget’s disease have a higher risk of developing vulval cancer.
  • Human papilloma virus (HPV) – this is a common infection, usually passed between people during sex. Some types of HPV are linked to vulval cancer. Most women with HPV don’t develop any problems and their immune system quickly fights the virus.
  • Vulval intraepithelial neoplasia (VIN) – this is a pre-cancerous condition that occurs in the skin of the vulva. Sometimes VIN can develop into vulval cancer.
  • Smoking – the risk of developing VIN and vulval cancer increases if you smoke.
  • Cervical intraepithelial neoplasia (CIN) or cervical cancer – women who have pre-cancerous changes in the cells of their cervix or who have had cancer of the cervix have a higher risk or developing vulval cancer.
  • Lowered immunity – having a low immune system can increase your risk.

Causes and risk factors of vulval cancer

The exact cause of vulval cancer is unknown. However, things called risk factors can increase a woman’s chances of developing it. Having one or more risk factors does not mean you will definitely get cancer. And if you don’t have any risk factors, it does not mean you won’t get vulval cancer.


Age

The risk of developing vulval cancer increases with age. Most of the women who are diagnosed with vulval cancer are aged 65 or over. Vulval cancer in older women is usually linked to a skin condition called lichen sclerosus (see below).

Vulval cancer is becoming more common in younger women, where it is often linked to human papillomavirus infection (HPV) (see below) and smoking.


Vulval skin conditions

Some long-term (chronic) skin conditions of the vulva can increase a woman’s risk of developing vulval cancer. These include:

  • vulval lichen sclerosus
  • vulval lichen planus
  • Paget’s disease.

Lichen sclerosus (LS) and lichen planus (LP)

Lichen sclerosus and lichen planus are fairly common, non-cancerous skin conditions. They can affect different parts of the body, but commonly affect the vulva. When they affect the skin of the vulva, they are known as vulval LS or LP.

Less than 5 in every 100 women who have vulval LS or LP (less than 5%) develop vulval cancer. It is thought that, over a long period of time, the inflammation caused by these skin conditions increases the risk of cancer developing.

Paget's disease of the vulva

This condition causes abnormal changes in the cells that cover the skin of the vulva. It is rare and usually only affects women who have been through the menopause. In a small number of women with Paget’s disease of the vulva, cancer is found underneath the area where the Paget’s disease is.


HPV

Human papilloma virus (HPV) is a very common infection. It is usually passed between people during sex. There are more than 100 types of HPV, and each has a number. Some types (particularly 16, 18 and 33) are linked to vulval cancer and pre-cancerous changes called VIN.

Most women with an HPV infection do not have any problems, as their immune system quickly gets rid of the virus. But in a few women, the virus stays and may cause abnormal changes in the skin of the vulva, and sometimes vulval cancer.

A vaccination against HPV is offered to girls aged 12 to 13 in the UK. This protects against HPV types 16 and 18.

It may take several years to see whether this vaccination reduces the number of vulval cancers. This is because vulval cancers can take a long time to develop.


Vulval intraepithelial neoplasia (VIN)

The term VIN describes changes that can happen in the skin that covers the vulva. If the changes become more severe, there is a chance that cancer might develop after many years. So VIN is called a pre-cancerous condition.

There are two types of VIN:

VIN usual type

This type is linked to HPV and mainly affects younger women aged 35 to 55.

VIN differentiated

This type is linked to lichen sclerosus and mainly affects women over the age of 55.


Smoking

Smoking increases the risk of developing both VIN and vulval cancer. The longer a woman smokes for and the more cigarettes she smokes, the greater the risk. Smoking makes the immune system less effective and less able to get rid of HPV. This may be one reason why it increases the risk of vulval cancer.


Cervical intraepithelial neoplasia (CIN) or cervical cancer

Women with pre-cancerous changes in the cells of the cervix (CIN), or those who have had cervical cancer, have an increased risk of developing cancer of the vulva. This may be related to shared risk factors, such as HPV infection and smoking.


Lowered immunity

The immune system is part of the body’s defence against infections. Having a lowered immunity because of illness or treatment can increase the risk of vulval cancer. This could be if:

  • you have HIV
  • you are taking medicines to suppress your immune system after an organ transplant.

If you are worried that you are at risk of developing vulval cancer because you have lowered immunity, talk to your GP or specialist nurse, if you have one. They will be able to give you further advice.

Back to Potential causes of vulva cancer

Human papilloma virus (HPV)

Human papilloma virus (or HPV) is a common infection. Some types of HPV can increase the risk of developing cancer.