Oral sex is the leading 'risk factor' for a throat cancer, expert says

• Oral sex is now the leading "risk factor" for a throat cancer, an expert said. 
• The leading cause of oropharyngeal cancer is human papillomavirus (HPV), Dr. Hisham Mehanna said.
• He said there has been a rapid increase in throat cancer cases in the West in recent decades. 

Oral sex is the leading "risk factor" for oropharyngeal cancer, a specific kind of throat cancer that affects the tonsils and back of the throat, according to a British expert 

In recent decades, there has been a "rapid increase" in throat cancer, possibly amounting to an "epidemic" in the West, Dr. Hisham Mehanna, a professor at the University of Birmingham's Institute of Cancer and Genomic Sciences, wrote in The Conversation earlier this week. 

While throat cancer is often considered to be a consequence of smoking, the main cause of oropharyngeal cancer is human papillomavirus (HPV) — which is also the main cause of cervical cancer. In both the US and the UK, oropharyngeal cancer is now more common than cancer of the cervix, he wrote.

Because HPV is sexually transmitted, "for oropharyngeal cancer, the main risk factor is the number of lifetime sexual partners, especially oral sex," Mehanna said.

"Those with six or more lifetime oral-sex partners are 8.5 times more likely to develop oropharyngeal cancer than those who do not practice oral sex," he added. 

Mehanna said there was also some evidence that yound adults were choosing oral sex as in an effort to abstain from penetrative sex.  

A study Mehanna recently conducted, however, showed that while about 80% of adults in the UK reportedly practice oral sex at some point in their lives — only a small number develop cancer. 

"The prevailing theory is that most of us catch HPV infections and are able to clear them completely," he wrote, saying a small number of people are unable to get rid of the viral infection because of a defect in their immune systems. 

In the patients who are unable to clear the HPV, "the virus is able to replicate continuously, and over time integrates at random positions into the host's DNA, some of which can cause the host cells to become cancerous," he said.

The highly-effective HPV vaccine is widely available and is often received by young girls to prevent cervical cancer, Mehanna said. Some countries have recommended that HPV vaccines should be gender-neutral, and Mehanna suggested that young boys should also receive the vaccine as a preventative measure. 

In other words, the increase in oropharyngeal cancer could be mitigated by practicing safer sex and being vaccinated against the virus. 

In 2013, the actor Michael Douglas highlighted the links between oral sex and throat cancer when he said it was partly to blame for his diagnosis. He added that he had also been a smoker and drinker, that combined can be the most siginifanct factors for triggering throat cancer.

The American Cancer Society estimates about 54,540 new cases of oral cavity or oropharyngeal cancer in 2023. About 20% of those diagnosed with these cancers are younger than 55, the organization said.