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