HPV and cancer
This information is about the human papilloma virus (HPV) and how it may increase the risk of cancer. HPV is known to increase the risk of cancer of the cervix. It may also increase the risk of cancers affecting other parts of the body, including the vulva, vagina, anus, mouth and penis.
The human papilloma virus (HPV) is a common group of viruses. Over 100 different types of HPV have been identified, and each is known by a number. HPV affects the skin and the mucosa (the moist membranes that line parts of the body, such as the insides of the mouth, throat and anus).
Some types of HPV are known to increase the risk of developing particular types of cancer and are known as high-risk HPVs. The types most often associated with cancer are types 16 and 18. High-risk HPVs can lead to abnormal changes in the cells, which is sometimes called dysplasia. Although dysplasia is not cancer, it's sometimes described as being pre-cancerous.
Other types of HPV can cause warts and verrucas. These may appear on different parts of the body, but are more commonly seen on the hands and feet, in the genital area and around the anus. The types of HPV that cause visible warts and verrucas are less clearly linked with cell changes that can increase the risk of cancer. They are known as low-risk HPVs.
This information is about the high-risk HPV types that can increase the risk of developing cancer.
There are around 40 different types of HPV that can affect the anogenital area (the cervix, vulva, anal area and penis). HPV is spread through skin contact, often during sex. Exactly how a person gets the virus is uncertain, and it's not always possible to find a sexual cause. It's thought there may be other ways of spreading the virus that have not yet been identified.
HPV can affect both men and women and because the virus is very common, most people who are sexually active will have HPV at some time during their life. Many people don’t have any symptoms and are unaware that they have HPV. The virus may be inactive for weeks, months, and - for some people - possibly even years after infection. The body’s immune system is usually able to get rid of an HPV infection, and for most people infections come and go without causing any problems.
Although HPV can increase the risk of developing some types of cancer, most people who have HPV won't develop cancer.
Reducing the risk of HPV infection
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If you are sexually active it may be difficult to avoid becoming infected with HPV.
As most high-risk HPVs don't cause symptoms, it can be impossible to tell whether your partner is infected. Using condoms and other barrier methods of contraception can help reduce the risk of becoming infected. But they don't cover all of the skin and are therefore not completely effective.
You're more likely to become infected with HPV if you start having sex at a younger age and if you have a lot of sexual partners, especially if you’re having sex without using a barrier method of contraception.
HPV infection may be more likely if there are abrasions or small cuts and tears in the skin or mucosa. Abrasions and tears are more likely to occur during anal sex, or if the vagina is drier than normal (for example following the menopause). In these situations it can help to use a lubricant during sex, such as Senselle®, Astroglide®,Sylk®, Vielle® or the range produced by Durex®.
As HPV infection is common (and difficult to prevent), it's important for people to be alert to any changes in the parts of the body where we know HPV may cause cancer. Cancer diagnosed in the very early stages, before it has begun to spread, is much easier to treat and cure. It's important that women have regular cervical smear tests, as these can pick up changes in the cervix at a very early stage.
There is some evidence to suggest that people who smoke and have HPV are more likely to develop cell changes that can lead to cancer than non-smokers who have HPV. If you know you have HPV, or even if you don’t know, stopping smoking may help to boost your immune system.
As there are usually no symptoms of high-risk HPV, the infection is often not diagnosed. There are no blood tests to detect HPV.
Diagnosis of HPV in women
HPV infection of the cervix is mainly diagnosed in women as a result of the cervical screening programme. A woman may be told she has HPV when she receives her cervical screening result.
If an HPV infection is present, changes in the appearance of the cells can sometimes be seen when they are looked at under a microscope during the screening process.
Testing of cervical screening samples for high-risk types of HPV is now being introduced in some areas of the country. This means that if you live in an area where it has been introduced, your cervical screening sample may be tested to see if it contains a high-risk type of HPV. This is explained in more detail in our information about cervical screening. You can also find out more at www.cancerscreening.nhs.uk
Some women who have an abnormal smear test result will attend a colposcopy clinic, where their cervix will be examined using an instrument like a microscope (called a colposcope). During the examination, the nurse or doctor can apply a solution to the cervix that makes cells infected with HPV turn white.
An HPV DNA test can sometimes be done using cells collected during a routine cervical screening test or colposcopy. This test can also be done during an anal smear – see below. The HPV DNA test looks at the genetic make-up (DNA) of the HPV within the cells and can detect which type of HPV is present. This can be useful, as it may help identify whether the HPV is a type that may cause pre-cancerous changes. HPV DNA tests aren't widely available in the UK.
Dr Richard Smith explains cervical screening, and how it can prevent cancer.
Diagnosis of HPV in men
In men, high-risk HPVs don't cause symptoms and are often very difficult to diagnose.
Some people who are known to be at a high risk of having anal HPV and of developing anal cancer may be offered an anal smear. Men who have anal sex are more likely to have anal HPV and are at an increased risk of developing anal cancer. The risk for men and women with HIV is greater still, regardless of their sexual orientation.
The anal smear is very similar to a cervical smear, and involves collecting cells from the anal area using a special wipe. An HPV DNA test (see above) can also sometimes be done during an anal smear. However, anal smears are not widely available in the UK. If you are in a high-risk group and more likely to have anal HPV, you can talk to your GP or a doctor at your local sexual health clinic, about whether you should have regular anal smears.
HPV and cervical cancer
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High-risk HPV can cause changes to the cells that cover the cervix. These changes are known as cervical intra-epithelial neoplasia (CIN). Not all women with these types of HPV develop CIN. For many women, HPV infection is temporary and any cell changes will go back to normal.
CIN is not a cancer but in some women, if left untreated, it can develop into cancer over a number of years. Treatment for CIN is very effective, and the risk of it coming back after treatment is low. Treatment will usually depend on how severe the abnormal changes are.
The changes are often graded as CIN 1, 2 and 3. CIN 1 may not need any treatment, but will be closely monitored by your doctor. CIN 2 and 3 can be treated using surgery, where the affected area of the cervix is removed by large loop excision (LLETZ) or, less commonly, by cone biopsy. The abnormal cells can also be removed by laser therapy, cryotherapy (freezing the area) or cold coagulation (heating the area).
CIN does not usually cause symptoms. Symptoms of cervical cancer include:
abnormal vaginal bleeding
bleeding after sex
abnormal vaginal discharge.
These symptoms can also be caused by many other things, but it's important to get any symptoms you have checked by your GP.
HPV vaccines and cervical cancer
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HPV types 16 and 18 are present in about 7 in 10 (70% of) cervical cancers. Because of this, two vaccines to prevent HPV infection have been developed. Large research trials using the vaccines Gardasil® and Cervarix® have shown that they can prevent HPV infection types 16 and 18 in nearly all women who are given the vaccine before they become infected. However, as cervical cancer can take many years to develop after HPV infection, it's too early to tell whether the HPV vaccines will help to prevent cervical cancer in the long term.
Since September 2008 there has been a national HPV vaccination programme for girls aged 12–13. Since September 2012 the vaccine used in this programme has been Gardasil. The vaccine is given as a series of three injections within a 12 month period. Apart from mild soreness at the injection site, there are very few side effects.
Women who have been vaccinated will still need to attend their routine cervical smear tests. This is because there are other types of HPV linked with cervical cancer, which the vaccines are not active against. The vaccines are not a substitute for cervical screening.
Although it's known that the vaccines help prevent HPV types 16 and 18, it is not known what the best age is for girls to be given the vaccines, or whether women will need a booster to keep them immune. As HPV is mainly spread by sexual contact, it isn't known whether boys should also be vaccinated.
The current vaccines only help prevent HPV infection. They don't treat an infection that is already present. However, research studies are looking at vaccines that could in the future be used as treatment for women who already have HPV.
High-risk HPV infection can cause cell changes in the vulval area (a woman’s external genitalia). The changes are known as vulval intra-epithelial neoplasia (VIN). Not everyone who has HPV will develop VIN. VIN is not cancer, but in some women it can develop into vulval cancer over many years. Not all VIN will develop into a cancer, although it's thought that high-risk HPV infection causes over half of all vulval cancers. Cancer of the vulva is rare - about 1000 women are diagnosed with it each year in the UK.
Treatment for VIN will depend on how severe the cell changes are. Mild changes (VIN 1) will usually only need to be closely monitored with regular outpatient appointments. Treatment may be needed if the cell changes are more abnormal (VIN 2 or 3). This usually involves removing the abnormal area using surgery, laser therapy or diathermy (which uses an electrical current to cut away the affected area).
Symptoms of vulval cancer include:
pain, discomfort and itching in the vulva
small lumps or swellings in the vulva
abnormal vaginal bleeding or discharge
a sore or ulcerated area on the vulva.
These can also be symptoms of other non-cancerous conditions, but it's important to get any symptoms checked by your GP.
The vaccines currently being researched to prevent HPV infection and CIN may also help prevent VIN. Trials using these vaccines are currently underway. Other vaccines, to be given to women who already have HPV, are being developed. They aim to boost the immune system to get rid of the HPV.
HPV and vaginal cancer
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High-risk HPV can cause cell changes to the cells that cover the vagina. The changes are known as vaginal intra-epithelial neoplasia (VAIN). Not everyone who has HPV will develop VAIN.
VAIN is not cancer, but in a few women it may develop into a vaginal cancer over many years. Not all VAIN will develop into a cancer. Cancer of the vagina is rare, and fewer than 300 women are diagnosed with it in the UK each year.
Treatment of VAIN will depend on how severe the cell changes are. Mild changes (VAIN 1) will usually only need to be closely monitored with regular outpatient appointments. More severe changes (VAIN 2 or 3) may need treatment, which usually involves either surgery to remove the abnormal cells, diathermy, laser therapy or chemotherapy creams. Sometimes radiotherapy is used.
Symptoms of vaginal cancer include:
blood-stained vaginal discharge
pain and discomfort in the vaginal area
bleeding after sex
difficulty or pain when passing urine.
These can also be caused by non-cancerous conditions, but it's important to get any symptoms checked by your GP.
Not much is known about HPV and anal cancer, but high-risk HPV can cause cell changes around the anus. The changes are known as anal intra-epithelial neoplasia (AIN).
Not everyone who has HPV will develop AIN. It occurs more often in men who have anal sex and in HIV-positive men and women.
AIN is not cancer, but in some people it can develop into anal cancer over many years. Anal cancer is rare in the UK - around 850 people are diagnosed with it each year. Treatment of AIN may involve surgery, which can affect the normal function of the anus. Usually, people who have AIN will have regular appointments to detect early signs of an anal cancer, when it is easier to treat and more likely to be cured.
Symptoms of anal cancer include:
bleeding from the rectum
pain, discomfort and itching around the anus
small lumps around the anus
difficulty controlling the bowels (faecal incontinence).
These can also be caused by non-cancerous conditions, such as piles (haemorrhoids). It is important to get any symptoms checked by your GP.
The vaccines currently being researched to prevent HPV infection and CIN may also help prevent AIN. Trials using these vaccines are currently underway.
HPV and head and neck cancers
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The high-risk HPVs, especially type 16, have been linked to cancers affecting the tonsils, tongue and pharynx (the area at the back of the throat). This type of HPV is most commonly transmitted during oral sex.
Head and neck cancers are more common in people who smoke, and especially those who also drink alcohol. However, about a quarter of head and neck cancers are diagnosed in people who have never smoked. It's thought that HPV may play a part in the development of some of these cancers. In the same way as HPV affects other areas of the body, the virus can lie dormant for many months or even years before causing cell changes that, in some people, may develop into cancer.
Most people who have HPV in their mouths will never develop any symptoms and won’t develop cancer. At the moment there is no way of detecting HPV in the head and neck area before a cancer is diagnosed. However, research trials using the HPV vaccines may help prevent HPV infection, which could reduce the number of people who develop head and neck cancers. Further research looking into the link between HPV and head and neck cancers is also being done.
Symptoms of a head and neck cancer include:
an ulcer or sore that doesn’t heal
difficult or painful swallowing
pain when chewing
a constant sore throat or hoarse voice
a swelling or lump in the mouth
a numb feeling in the mouth or lips.
Any symptoms that you are unsure about, or that have persisted for a couple of weeks, should be checked by your GP.
HPV and cancer of the penis
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Some research studies suggest high-risk HPV, especially type 16, is a possible cause of cancer of the penis, although its exact role in the development of this type of cancer isn't clear. There is no established HPV test for men, and many men will never know that they have HPV infection of the penis. Because of this, it's important that men are aware of the early signs of penile cancer.
Cancer of the penis is rare, and approximately 500 men are diagnosed with it each year in the UK. It can often be treated very successfully if it's diagnosed early. Many of the symptoms of penile cancer can also be symptoms of other conditions, but should always be checked by your GP or a sexual health doctor.
Symptoms of penile cancer include:
a change in colour of the skin of the penis
thickening of the skin of the penis
a growth or sore, especially under the foreskin
discharge and bleeding.
Many people feel concerned when they are first told that they have HPV, and worry that they may develop cancer. You may find the treatments embarrassing, and you may have many different emotions, including anxiety and fear. These are all normal reactions and are part of the process many people go through in trying to come to terms with their condition.
Everyone has their own way of coping with difficult situations. Some people find it helpful to talk to family or friends, while others prefer to seek help from people outside their situation. Others may prefer to keep their feelings to themselves. There is no right or wrong way of coping, but help is available if you need it. You may wish to contact our cancer support specialists for information about counselling in your area
This information has been compiled using information from a number of reliable sources, including:
CancerStats. Cancer Research UK. www.cancerresearchuk.org/cancerstats (accessed September 2012).
Castle P, et al. Human papillomavirus (HPV) vaccine (beyond the basics). August 2012 (accessed September 2012).
Elkas J, et al. Vulvar cancer: Clinical manifestations, diagnosis, and pathology. August 2012 UpToDate. www.uptpdate.com (accessed September 2012).
Gearhart P, et al. Human Papillomavirus medscape reference –drugs, diseases and procedures. August 2012 (accessed September 2012).
Lynch D, et al. Carcinoma of the penis: Epidemiology, risk factors, and clinical presentation. July 2012. UpToDate. www.uptodate.com (accessed 2012).
Mork J,et al. Human papillomavirus infection as a risk factor for squamous-cell carcinoma of the head and neck.
New England Journal of Medicine. 2001. April 12; 344(15): 1125-31.
Palefsky J, et al. Virology of HPV and the link to cancer. July 2012. UpToDate. www.uptodate.com (accessed September 2012).
Tobias J, Hochhauser D. Cancer and its management. 6th edition. 2010. Wiley Blackwell.
With thanks to Professor David Luesley, Professor of Gynaecological Oncology, and all of the people affected by cancer who reviewed this information.