Oral sex and smoking risk for mouth cancer
Men who smoke and have oral sex with five or more partners have the highest risk of developing HPV-related oropharyngeal cancer caused by exposure to the human papilloma virus (HPV), according to research published in Annals of Oncology (doi.org/10.1093/annonc/mdx535).
The researchers analysed data from 13 089 people, aged 20–69, who had been tested for oral HPV infection. They investigated the prevalence of cancer-causing HPV found in oral rinses and the numbers of new cases of oropharyngeal squamous cell cancer – the commonest type of oropharyngeal cancer.
The researchers found that among men the lowest risk group were those who had one or no oral sex partners in their lifetimes, with a prevalence of oral HPV infection of 1.5%; prevalence rose to 4% among nonsmokers with two to four oral sex partners. Risk of infection rose further among men who smoked and had two to four oral sex partners, with a prevalence of 7.1%, rising to 7.4% among those who did not smoke but who had five or more oral sex partners. The prevalence of infection was highest (15%) among men who smoked and had five or more oral sex partners.
There are over 100 different kinds of HPV, but it is HPV16 that causes most oropharyngeal cancer. The incidence of oropharyngeal cancer is predicted to overtake cervical cancer in the USA by 2020.
‘For this reason, it would be useful to be able to identify healthy people who are most at risk of developing oropharyngeal cancer in order to inform potential screening strategies’, says Dr Amber D’Souza, associate professor at the Johns Hopkins Bloomberg School of Public Health, one of the authors of the study.