Alarm bells went off around the world when 68-year-old Hollywood actor Michael Douglas said in an interview published in a British newspaper that oral sex had given him throat cancer.
But such cases appear to be far less common in Singapore, doctors said. Oral cancer cases are rare in Singapore, to begin with.
The human papillomavirus (HPV), while more commonly linked to cervical cancer in women, can cause cancer in some parts of the tongue and throat.
However, only 10 per cent to 20 per cent of oral cancer cases at the National Cancer Centre Singapore are linked to HPV, said Dr Tan Ngian Chye, a senior consultant in surgical oncology.
The centre routinely tests oral cancer patients for the virus, which can be transmitted through regular, anal or oral sex.
There are more than 100 types of the virus but HPV-16 is the one most commonly linked to oral cancer - especially cancer that arises at the base of the tongue, tonsils or the soft palate of the mouth.
These areas, known collectively as the oropharynx, contain lots of lymphoid tissues that "have an affinity for viruses", said Dr Tan. In the United States, about 75 per cent of cancers affecting these areas are linked to HPV infections.
But at the National University Hospital (NUH), the rate is less than 25 per cent, according to preliminary findings from an ongoing research study. Said NUH head and neck surgeon Lim Chwee Ming: "Most oral cancers are still caused by smoking or drinking. It can be difficult to pinpoint what the role of HPV is in causing the cancer."
In general, if a patient is young and does not smoke or drink alcohol regularly, HPV may be a possible reason for the disease - especially if it happens at the oropharynx, added Dr Lim.
Someone who appears to tick these boxes is a 42-year-old manager who wants to be known only as Michelle. She contracted throat cancer at the age of 38 and blames oral sex for it. Her former boyfriend, who slept around, had a particular fondness for oral sex. Tests show that her cancer tissue contains HPV.
The risk of getting an HPV infection, however, remains low.
Nearly all adults who have had sex get the virus at some point in their lives. But 90 per cent of the infections go away on their own.
Parkway Cancer Centre's Dr Lim Hong Liang said men are about three times more likely than women to contract HPV-related oral cancer. The reasons are unclear.
Overall, oral cancer is uncommon in Singapore. Between 2003 and 2007, about 400 cases of mouth and tongue cancer were reported to the Singapore Cancer Registry.