Sometimes it takes a celebrity to “own” a cancer before we sit up and take notice. Until actor Michael Douglas announced that his throat cancer was related to HPV, most of us were clueless that this virus was linked to any cancer other than cervical cancer in women.
Yet HPV, the common human papilloma virus which can be sexually transmitted through vaginal, oral and anal sex (and, yes, kissing), is connected to a surprisingly long list of cancers in both sexes – cancer of the tonsils, throat, vulva, vagina, penis and anus.
Two of these cancers are on the rise in Australia – and HPV is the likely cause. Anal cancer is one and cancer of the tonsils (or oropharynx) – the type that affected Michael Douglas – is the other.
What began as a soreness in the gum behind a molar turned out to be cancer, Douglas told a meeting of oncologists in 2014.
“Both anal and oropharyngeal cancer can be caused by HPV,” says Megan Smith, Program Manager of the Cervical/HPV and Breast Group with the Cancer Council NSW.
“Both sexes are affected, although oropharyngeal cancer is more common in men and anal cancer is more common in women. Although many head and neck cancers are decreasing in Australia thanks to less smoking, oropharyngeal cancer is increasing.”
The HPV virus was found in 91 per cent of cervical and anal cancers, 75 per cent of vaginal cancers, 69 per cent of vulvar cancers, 63 per cent of penile cancers and 70 per of oropharyngeal cancers, according to US research reported last year in the Journal of the National Cancer Institute.
In Australia there’s a one in 49 risk of having head and neck cancer by the age of 85, says Dr Nham Tran, a researcher into early detection for head and neck cancer at the University of Technology, Sydney.
“The risk is higher in men – around 769 men will die from head and neck cancer in Australia this year, compared to 247 women,” he says.
Should we be worried?
First the good news: the HPV vaccine is helping to shrink the numbers of Australians carrying the virus by vaccinating 12 to 13 year old girls and boys through a free program – girls have been offered the vaccine since 2007 and boys since 2013.
“The fact that so many young women are now protected from HPV has also helped bring down rates of infection in men up to the age of around 30,” says Smith.
But there are still some gaps.
An estimated 20 to 30 per cent of young men and women in Australia, especially in the 21 to 26 age group, are not protected against HPV, according to Tran – either because they haven’t had the vaccine or didn’t complete the full course of three doses.
“We need more awareness about oral cancer and its links to HPV. Young men and women who haven’t had the vaccine risk being infected by HPV which is a direct cause of oropharyngeal cancer in Australia. There is also the risk of them developing ano-genital cancers as well,” he says.
But unless you’re a 12-13 year-old eligible for the program, the vaccine isn’t cheap – the cost of three doses is $450.
“It’s a personal choice – it’s very effective in adolescents but also very expensive and may not be effective in older adults because they’ve potentially been exposed to the virus. There’s also the fact that rates of HPV infection are dropping,” says Smith.
But while the vaccine may be pricey, so is cancer treatment.
“The average lifetime treatment cost of each new cancer case is estimated to be more than $25,000,” Tran points out. “Making the vaccine available free of charge or at least subsidised to those who’ve missed out would decrease the risk of HPV-related cancers.”
What if you’re older than 26 – is it worth having the vaccine? It’s complicated. For men, the vaccine is only available up until the age of 26, but for women it’s available up until 45 because their risk of HPV-related cancer is higher, says Smith.
But while HPV has a big role to play in oropharyngeal cancer, let’s not forget the impact of smoking and drinking on most head and neck cancers – with cancer of the tongue, gum, mouth, nasal cavity and larynx, alcohol and tobacco are the major risk factors, she adds.