Dr. Hisham Mehanna, from the UK's University of Birmingham, said 70 percent of cases of throat cancer are caused by human papillomavirus (HPV), a
normally harmless virus that is spread sexually and has been linked to multiple forms of cancers.
Dr. Mehanna said people with multiple oral s** partners have an up to nine-fold increased risk of throat cancer. He wrote in The Conversation: 'Over the past two decades, there has been a rapid increase in throat cancer in the west, to the extent that some have called it an epidemic.
'This has been due to a large rise in a specific type of throat cancer called oropharyngeal cancer.'
Oropharyngeal cancer is the most common type of throat cancer. It appears in the tonsils and back of the throat.
Doctors consider HPV infection to be the biggest risk factor for developing the disease.
Dr. Mehanna continued: 'HPV is sexually transmitted. For oropharyngeal cancer, the main risk factor is the number of lifetime sexual partners, especially oral s**.
'Those with six or more lifetime oral-s** partners are 8.5 times more likely to develop oropharyngeal cancer than those who do not practice oral s**.'
More than 50,000 cases of oral or oropharyngeal cancer are diagnosed in the US each year, causing more than 10,000 annual deaths.
The number of cases is growing, however, up to 1.3 percent a year in women and 2.8 percent in men, according to the American Cancer Society.
Doctors have found that oral s** is the biggest risk factor for them outpacing smoking, alcohol consumption, and an unhealthy diet.
This is because the acts can lead to an HPV infection at the back of the throat or near the tonsil.
These infections go away on their own in most cases but sometimes can persist and cause cancer.
Scientists at NYU Langone estimate that as much as 70 percent of throat cancer cases are caused by HPV infections.
In the UK, head and neck cancers combined are responsible for more than 12,000 cases and 4,000 deaths per year.
HPV is a common virus spread through vaginal, anal, and oral s** with someone who is already infected