Australia researchers say the human papillomavirus (HPV), which can cause cervical cancer in women, is now a leading cause of oral cancer among men in the Western world.
The announcement triggered debates over whether the HPV vaccine which is free for young women, to be offered to men. Based on a study by University of Sydney, 60 per cent of throat and tonsil cancers are caused by the virus.
Barbara Rose, Associate Professor in research at the University of Sydney says, We've tested just over 300 cancers of the oropharynx and the oropharynx includes the tonsil and the base of tongue and part of the pharangyl wall.
We've tested those for human papillomavirus type-16 and type-18, which are the major cause of cervical cancer in women.
And we found a sizeable proportion is associated with those types. In fact, probably in excess of 50 per cent now.
There was a nearly 60 per cent rise in 2006-07 compared to the figures back in 2001-05. Head and neck cancers have traditionally been associated with older men and related to alcohol and smoking habits, says Associate Prof Rose.
The new findings show that has changed and most are due to the increasing practice of oral sex.
We now know that there's another subset, which quite distinct biologically, which tends to affect younger people who don't smoke and don't drink, caused by human papillomavirus probably by sexual transmission, she said.
And the types of papillomavirus that are associated are type-16 and type-18 which are the major cause of cervical cancer.
Australia has been giving out cervical cancer vaccine Gardasil to young women for the past two years in the immunization against HPV. Associate Prof Rose says the findings should prompt discussions about extending the vaccination to boys as well.
The paper that we just published gives some indication of the numbers of cancers that potentially preventable down the track by vaccinating boys, she added.
The rate of HPV cancers in men is rising, says Dr Jonathan Clark, a head and neck surgeon at Royal Prince Alfred and Liverpool Hospitals in NSW.
Dr Clarks believes extending the vaccination to boys is worth considering, and is worthy of further research.
Tonsil cancers occur in an older group of patients. Though HPV tonsil cancers tend to occur in younger people who don't smoke, but they develop over many years, he said.
So it is going to take quite a bit of time to see whether the introduction of HPV vaccine actually has an effect of reducing the rate of tonsil cancer.