The number of oral cancer cases diagnosed each year in the U.K. has risen above 6,000 for the first time, according to new data released today by Cancer Research UK.
A decade ago there were approximately 4,400 cases of oral cancer in the U.K. But the latest figures show there were 5,905 cases of oral cancer in 2008 in the U.K., and 6,236 cases in 2009. Around two-thirds of cases are in men.
Oral cancer rates in the U.K. have risen by about 25% in the last 10 years, from six to eight cases per 100,000 people, according to the agency.
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. Eight out of 10 people in the U.K. will be infected with HPV at some point in their lives, Cancer Research UK said.
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, and most people will never know they had the virus. But a few strains of HPV are high-risk and can lead to cell changes that can develop into cancer. One of these high-risk strains is HPV-16.
"We have seen a rapid increase in the number of HPV-16-positive cases of oral cancer," said Richard Shaw, a Cancer Research UK expert in head and neck cancers, in a press release. "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 tumors 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."
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, the agency noted. And while figures show that the amount of alcohol bought in the U.K. over the past 20 years has increased by 7%, 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.
The new Cancer Research UK data also found particularly sharp rises in the incidence rates of cancers at the base of the tongue (almost 90% increase) and the tonsil (around 70% increase), two areas of the mouth where cancers are more commonly HPV-related.
