Can throat cancer really be caused by an STD?

By: Robert L Ferris, MD, PhD, FACS

There has been a good deal of news lately about whether or not Michael Douglas’s throat cancer was caused by oral sex. Human Papillomavirus (HPV) is a disease transmitted through normal sexual activity, according to the National Cancer Institute. HPV may cause warts or bumps on the skin and the lining of the mouth, throat, genitals, and anal area – although some people don’t experience any symptoms. A person’s immune system may even clear the virus without any treatment. In recent years, the medical community has learned that HPV can lead to cancer, including cervical cancer and throat cancer, in both men and women. Most individuals exposed to HPV will not contract HPV-induced cancer.

How is HPV spread?
HPV can spread when the skin or mucosa (lining of the mouth) comes into contact with an infected person’s skin or mucosa. For high-risk HPV, this typically happens through sexual contact or activity. Although nearly everyone is exposed to HPV by adulthood, an extremely low chance of persistent infection occurs. Scientists believe that most HPV infections that lead to throat cancer are spread through oral sex, and possibly by deep kissing. If a patient has been diagnosed with an HPV infection by a medical professional, it is likely that their sexual partner has also been exposed to the virus. A female with genital tract exposure to HPV should follow normal women’s health guidelines, which includes routine Pap tests. There are no diagnostic tests available to detect HPV-related infection or pre-cancer in the mouth or throat. A new lump in the neck or symptoms like worsening trouble swallowing, throat pain, or bleeding should be discussed with a physician.
How does HPV cause head and neck cancer?
Most people are exposed to HPV in their youth. In the majority of people, the infection is cleared spontaneously. Some people display warts, while a few people exposed to high risk HPV may be unable to rid the body of the virus. Scientists are not yet able to predict a person’s susceptibility to developing an HPV-related cancer. Currently, the period between high risk HPV infection and the development of cancer is unknown, however, most scientists believe it takes many years. If a cancer is diagnosed, physicians can test the tumor to determine if it is related to HPV. This is important because HPV status can determine prognosis in treating the tumor.

Why is HPV status important?
It has been found that patients with HPV-positive throat cancer have better outcomes than those with throat cancer that is not related to HPV. Both types of cancers are treated the same way — with a combination of surgery, radiation, and/or chemotherapy. Oncologists make treatment decisions based on the size and location of the tumor, the stage of the disease, and the overall health of the patient, taking the patient’s preferences into consideration. Current clinical trials are focused on whether to treat HPV-related cancers differently than non-HPV cancers.

Do tobacco and alcohol use affect HPV and throat cancers?
Alcohol and tobacco are common risk factors associated with throat cancers. However, HPV-related throat cancer can develop in patients without a history of alcohol or tobacco use. It is strongly recommended that patients with throat cancers stop tobacco use and minimize their use of alcohol to decrease the risk of developing a second cancer.

Should I get the HPV vaccine?
The HPV vaccine is currently aimed at preventing genital warts and cervical cancer, and is recommended for all boys and girls between the ages of 11 to 24, before sexual exposure. There also is possible evidence the vaccine may protect against HPV-related throat cancer; however this has not yet been proven. In either case, the vaccine is only effective if given before HPV infection occurs. There is no proven benefit from the vaccine for people diagnosed with HPV-related cancer.

HPV+ throat cancer is one of the fastest growing types of cancer among men. Recently, the annual number of HPV-positive throat cancers has surpassed the annual number of cervical cancers in part because no proven screening method exists for throat cancer (like a pap test can find cervical pre-cancers early). While I have not personally examined Mr. Douglas, or his files, and although there have been denials about the cause, it is entirely possible that Mr. Douglas’s cancer was caused by HPV.