Oral cancer rates are on the up with 6,065 people in England being diagnosed in 2010 – a steady increase from the 5,500 oral cancer patients diagnosed back in 2008. As well as referring to head and neck cancers, oral cancers can cover the mouth, lip and tongue, as well as cancers of the tonsils, oesophagus, larynx (voice box), nasopharynx (the area that connects the nose and throat) and the thyroid gland. But what is causing this rise in numbers?
Some are pointing the finger at sexually transmitted human papilloma virus (HPV) infection, which has been linked to cancer on numerous occasions. Although the main causes of oral cancer have been labelled as drinking too much alcohol and smoking, HPV is now a growing consideration, with 25% of mouth and 35% of throat cancers being linked to the infection. HPV is not said to cause the cancer, but instead becomes part of the genetic material of the cancer cells, encouraging them to grow.
How do you get HPV in the mouth?
The types of HPV that are found in the mouth are usually sexually transmitted, so oral sex is the prime route of the infection reaching that area, although high risk HPV can also be passed through vaginal and anal sex. Some forms of the infection can be contracted through skin to skin contact, such as genital warts, however this is not the same strand as the one linked to cancer.
Most sexually active people (about 90%) will have been exposed to either high or low risk genital HPV types by age 25, but only 2-3% of these people develop visible genital warts. So most of us have been infected, but few are affected. It’s not known how common HPV infection in the mouth is, although a study carried out in 2009-10 concluded that the prevalence of oral HPV infection in American men was 10%, and in women 3.6%.
The study also revealed that the main risk factors were age (with peaks in the 30-34 and6 60-64 age bands), the number of sexual partners that you have had (high risk would include more than 20 partners) and number of cigarettes smoked per day. Sexual behaviour could also be linked to oral cancer, for example having oral sex with more than four partners or first having sex when you younger (under 18 years old).
How does HPV link to cancer?
HPV does not directly give you cancer but it can causes changes in the cells it has infected (for example, in the throat or cervix), and these cells can then become cancerous. Very few people infected with HPV will develop cancer, as in 90% of cases the infection is cleared naturally by the body within two years.
However, people who smoke are much less likely to clear the virus from their body. This is because smoking damages special protective cells in the skin called immune surveillance cells, allowing the virus to persist. If cell changes do happen, it can take a long time – even decades. HPV-related oral cancers seem to respond better to treatment than non-HPV-related oral cancers.
Is there a HPV vaccine?
Since nearly all cervical cancers are HPV-related, girls aged between 12 and 13 in the UK are vaccinated against HPV, which also protects women from HPV-related vulval and vaginal cancers. The jab is also said to work against anal and oral cancers since these work in a similar way. Currently, men are not given this vaccination.
What are the symptoms of oral cancer?
- red – or red and white – patches on your tongue or the lining of your mouth
- one or more mouth ulcers that do not heal after three weeks
- a swelling in your mouth that lasts for more than three weeks
- pain when swallowing
- a feeling as though something is stuck in your throat
Please ensure you see your GP as soon as possible if you feel you have any of these symptoms.
