In a recent interview, Michael Douglas states that his throat cancer was not the result of a common culprit like smoking or drinking. Rather, his cancer came about because of an STD known as human papillomavirus (HPV).

The Oscar-winning actor also told The Guardian that he is cancer-free after several months of chemotherapy and radiation, but that he has frequent checkups to catch any recurrence.

The specific type of HPV, called HPV16, has been linked to oral cancer. Often times, oral cancer is overlooked.  For Michael Douglas, by the time they diagnosed his throat cancer, he was in Stage IV with a walnut-sized tumor in his throat.

A report in Women’s Health Magazine tells the story of a woman with a swollen lymph node actually having Stage III oral cancer that had spread from the tonsils to the lymph nodes.

HPV is the most common STD.  There are more than 100 variants, and some do not require sexual contact in order to be spread to others.  Each variant manifests in different ways and some show no symptoms.  HPV is so common that it is estimated that, by the age of 25, 90 percent of individuals that are sexually active will have been exposed.

A study linking HPV to oropharyngeal cancer found an increase of 225 percent in rates of such HPV-related cancer between 1998 and 2004. HPV is best known as being the cause of cervical cancer. However, at present rates of increase, HPV will cause more oral cancers than cervical ones by 2020.

Another study, published in the Journal of Clinical Oncology, actually found that HPV is the cause of more oral cancers than tobacco or alcohol. Smoking triples the risk of cancer and drinking increases the risk of cancer by 2.5 times. A study in the New England Journal of Medicine estimated that HPV made people 32 times more likely to develop oral or throat cancers.

Medical professionals recommend safe sex practices to protect individuals against HPV infection. Taking such precautions can prevent contracting HPV variants that are spread through genital contact.  Unfortunately, one study suggests that kissing can also spread some types of HPV.  This means that even abstaining from sex does not ensure full protection from HPV.