Men who have performed oral sex on five or more women are at greater risk of developing head and neck cancer, especially if they smoke.
Oropharyngeal cancer can be triggered by contracting the human papilloma virus (HPV), which is a common cause of cervical cancer in women.
Although the risk of diagnosis remains low – just 0.7 per cent of the male population – US researchers warned that men are more likely than woman to contract it.
According to the research, published in the journal Annals of Oncology, 15 per cent of men who smoked and had five or more oral sex partners are most likely to get HPV.
Around seven per cent of men who smoke and have had two to four oral sex partners contract the infection.
And the lowest risk group were those who had one or no oral sex partners in their lifetimes, with only 1.5 per cent of them getting an oral HPV infection. This rises to four per cent among non-smokers with two to four oral sex partners.
The risk was much lower among women, anyone who did not smoke, and people who had less than five oral sex partners in their lifetimes.
One of the authors of the study, Dr Amber D’Souza, said cases of head and neck cancer are predicted to overtake cervical cancer by 2020 and said that, because of this, an effective screening process was crucial.
“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, if effective screening tests could be developed,” she said.
“Most people perform oral sex in their lives, and we found that oral infection with cancer-causing HPV was rare among women regardless of how many oral sex partners they had.
“Among men who did not smoke, cancer-causing oral HPV was rare among everyone who had less than five oral sex partners, although the chances of having oral HPV infection did increase with number of oral sexual partners, and with smoking.”
Researchers analysed data from 13,089 people, aged 20-69.They used the numbers of oropharyngeal cancer cases and deaths from US registries to predict the risk of cancer from oral HPV infection.
There are over 100 different kinds of HPV but only a few are known to cause cancer. HPV 16 or 18, for example, is known to cause most cervical cancer, and HPV 16 also triggers oropharyngeal cancer.