Three years after his diagnosis, actor Michael Douglas told The Guardian that his throat cancer may have been caused by the human papillomavirus contracted through oral sex. His statement put the spotlight on a larger public health issue.
Smoking and drinking are also significant risk factors for throat cancer. CNN's Chief Medical Correspondent Dr. Sanjay Gupta explains that doctors can test to determine if there's a direct link between HPV and cancer.
"What they're searching for is DNA of the virus ... and if they find it, then they can almost definitively say that this was caused by the HPV infection."
HPV is thought to cause 1,700 oropharyngeal, or throat, cancers in women and 6,700 oropharyngeal cancers in men each year, according to the CDC.
For patients whose cancer was caused by HPV, Gupta says the prognosis may be better compared to patients who became sick from tobacco and drinking because they have a better response to the treatment.