HPV and cancer
Infection with human papillomavirus (HPV) increases the risk of some cancers. Most people will be infected with HPV at some point in their lives and it usually doesn’t cause any problems at all. You can help protect yourself against HPV infection by getting vaccinated if you are eligible.
What is HPV?
The human papillomavirus, or HPV, is a type of virus that infects the skin and the cells lining body cavities. For most people, the infection will get better on its own and they will never know they had it. There are hundreds of different types of HPV:
- Some infect the skin, usually on the fingers and hands. These can cause minor problems, such as common skin warts and verrucas.
- Others infect the genitals, mouth and throat. These can cause genital warts, or more rarely, cancer.
From this point onwards, we’ll only be talking about genital and oral HPV, as these types are the ones which can cause cancer.
HPV is a very common infection. Around 8 out of 10 people will be infected with the virus at some point in their lives. It usually doesn’t cause any symptoms and most people will never know they had it. HPV spreads through close skin-to-skin contact, usually during sexual activity including oral sex. Having a high number of sexual partners does increase your chances of infection. But it’s important to remember that you can still pick up an infection at any time.
HPV infection usually causes no problems at all. But in some people the infection will stay around for a long time and become persistent. Around 13 types of HPV can cause cancer. These are called ‘high-risk’ types. People with persistent infections with ‘high-risk’ HPV types are those who are most likely to go on to develop cancer.
What cancers are linked to HPV?
The main type of cancer linked to HPV infection is cervical cancer. Virtually all cases of cervical cancer are caused by HPV. About 3,100 cases of cervical cancer are diagnosed in the UK each year.
HPV can also cause cancers in other genital areas, like the vagina, vulva, penis, and anus,. It can also cause some types of cancer of the mouth and throat.
The majority of vaginal, vulval, penile and anal cancers are caused by HPV. But they are less common than cervical cancer. Men who have sex with men may be at increased risk of anal cancer.
HPV infection also increases the risk of some types of mouth and throat cancers. Rates of mouth cancer, especially tongue and tonsil cancers, are on the increase, particularly in people in their 40s, 50s and 60s.30–34 And the evidence suggests that the proportion of cases linked to HPV is rising.
How can HPV cause cancer?
HPV can cause cells to divide more than usual. Fast cell growth can cause warts to develop, but often it doesn’t cause any symptoms at all. The types of HPV that cause warts are not the same types that cause cancer.
In persistent ‘high-risk’ HPV infections, the virus can damage DNA and cause cells to start dividing and growing out of control. This can lead to cancer.
Reducing the risk
HPV infections are mostly spread through direct skin-to-skin contact, usually during sexual activity. No matter the sex of your partner, using a barrier protection method like a condom reduces the risk of passing on HPV infections. But it isn’t completely effective.
It’s important to understand that while the virus can spread through skin-to-skin contact, you cannot directly pass on HPV-linked cancers.
For cervical cancer, attending screening is a very effective way of reducing the risk of developing the disease.
The HPV vaccine also helps protect against cancer. The vaccine is offered to girls aged 11-13. Men who have sex with men can request the vaccine through sexual health clinics.
How the HPV vaccine works
HPV can cause changes to the DNA in our cells that make them more likely to turn cancerous. So by protecting against HPV infection, we can help prevent those changes and reduce the risk of cervical cancer.
HPV vaccination for women
Since 2008, girls aged 11-13 have been offered a vaccination against the two most common ‘high-risk’ types of HPV, HPV 16 and 18. Together, these two types cause about 7 out of 10 cervical cancers. Girls up to the age of 18 can request vaccination through the NHS if they weren’t vaccinated routinely. The HPV vaccine has been proven to be safe and effective.
The HPV vaccine currently used in the UK (Gardisil) also protects against HPV 6 and 11, which are the HPV types that cause the majority of genital warts.
The HPV vaccine doesn’t protect against all types of HPV, so screening is still important, even if you have been vaccinated.
HPV vaccination for men
As HPV is linked to cancers in men as well as women, offering HPV vaccination to men would help reduce the risk of disease. In particular, men who have sex with men have a higher risk of anal cancer than men who don’t.
From April 2018, the vaccine is being rolled out men who have sex with men in all sexual health and HIV clinics across the UK.
The Joint Committee for Vaccination and Immunisation are also currently considering whether to offer HPV vaccination to all teenage boys as well as girls.
HPV and Cervical Screening
The UK has a screening programme for cervical cancer. Taking up your invitations is a great way to reduce the risk of cervical cancer.
Cervical screening aims to pick up early cell changes that are caused by HPV, and remove these cells before they have a chance to become cancerous. This is done by taking a sample of cells, and sending them to a lab where they are tested to see if they are normal (cytology). If the cells look abnormal, they will be tested for HPV to see if they are more likely to become cancerous. If they test positive for HPV, the cells will be removed.
But soon the order of the tests will switch. Cells will be tested for HPV infection first, and only those that have the virus will be examined for signs the cells aren’t normal. This change to HPV primary testing will happen across England, Scotland and Wales by December 2019.
Testing for HPV first is a better way to screen for cervical cancer because all cervical cancer cases in the UK are linked to HPV infection. It will be able to save even more lives than the current test and also help avoid unnecessary procedures for women.