The number of oral cancer cases diagnosed each year in the UK has risen above 6,000 for the first time, new figures from Cancer Research UK show today.
A decade ago there were over 4,400 cases of oral cancer. Now the latest figures show this has risen to over 6,200. Around two thirds of cases are in men.
Oral cancer rates in the UK have risen by around a quarter in the last 10 years from around six to eight cases per 100,000 people.
Experts believe that infections with high-risk strains of the human papillomavirus (HPV) may be a key reason for the jump in cases of oral cancer.
HPV infections are common with up to eight out of 10 people in the UK infected at some point in their lives.
Infections are usually on the fingers, hands, mouth and genitals. Many strains of the virus cause infections that are harmless and get better on their own. Most people will never know they had the virus.
But a few strains of HPV are known as high-risk. If these strains persist they can lead to cell changes which could develop into cancer. One of these high-risk strains is HPV-16.
Richard Shaw, a Cancer Research UK expert in head and neck cancers, based at the Liverpool Cancer Research UK Centre, said: "We have seen a rapid increase in the number of HPV16-positive cases of oral cancer. We have also noticed that patients with HPV-related oral cancers tend to be younger, are less likely to be smokers and have better outcomes from treatment than those whose tumours show no evidence of HPV.
"This raises questions as to exactly how these cancers develop and why they only affect a small proportion of people who are exposed.
"As HPV-related cancers appear to behave quite differently, the Liverpool Cancer Research UK Centre is also involved in Cancer Research UK-funded clinical trials to improve treatments."
Traditionally, the main risk factors for oral cancer have been tobacco and alcohol. Oral cancers tend to take at least a decade to develop so looking at lifestyles 20 to 30 years ago can help understand the rise in cases.
Over the last 30 years, smoking rates in Britain have more than halved.
And while figures show that the amount of alcohol bought in the UK over the last 20 years has increased by 7 per cent - this is unlikely to be a large enough increase to explain fully the rise in the rates of oral cancers.
Experts say this suggests other risk factors may be playing a role - in particular HPV.
There were particularly sharp rises in the incidence rates of cancers at the base of the tongue (almost 90 per cent increase) and the tonsil (around 70 per cent increase) - two areas of the mouth where cancers are more commonly HPV-related.
Sara Hiom, director of information at Cancer Research UK, said: "It's worrying to see such a big rise in oral cancer rates. But like many other cancers, if oral cancer is caught early, there is a better chance of successful treatment.
"So it's really important for people to know the signs and symptoms of oral cancer - mainly mouth ulcers that just won't heal, any lumps or thickening in the mouth, lips or throat, or red or white patches in the mouth that won't go away.
"It's not just doctors who have a vital role to play. If you're worried about any of these symptoms you can see your dentist as well.
"Dentists have an important role to play in spotting oral cancer early and encouraging their patients to take care of their mouths. So make sure you attend regular dental check-ups."
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