What is HPV?
HPV stands for Human Papilloma Virus, an extremely prevalent virus that infects the skin and mucous membranes of people. Infection can cause warts (papillomas) on the skin or mucous membranes of the genitals/mouth/throat and upper airway. There are over 100 types of HPV.
HPV infection is extremely common and usually harmless. Up to 50% of people are thought to be infected with a strain of HPV at any given time, often without any symptoms. Infection with HPV is usually cleared by the body, but can also remain for years and be chronic. It is not known why some people clear the virus from their bodies and others don’t.
The HPV virus has lived with people for a long time and is not new. Literally every adult in the United States has been infected with at least one strain of HPV at some point in his or her life.
What does HPV have to do with ENT?
About 40 types of HPV affect the mucous membranes, causing papillomas in the upper airway and genital area. There are only a few strains considered “high risk” in that they are associated with the development of cancer in these areas. Infection with “high-risk” strains can lead to the development of cancer of the cervix and in the mouth/throat because of the changes that the virus causes in infected cells.
Because HPV infection is so common, it is estimated that up to 90% of people have been exposed at some point to a high-risk strain of HPV. Up to 70% of people show evidence of previous infection with a high-risk strain due to the presence of antibodies in their blood. However, only about 1% of people show evidence of active oral infection with a high-risk strain of HPV. Most of these people will not develop oral/throat cancer, but they are at increased risk. We don’t know why some people with high-risk HPV develop cancer and others do not.
Infection with oral HPV is thought to be mostly from oral-genital contact or from passage through an infected birth canal (in the case of children). It is believed that changes in peoples’ behavior have encouraged the spread of HPV and the increase in HPV infection. HPV is now the most common sexually transmitted disease and the rapid increase of HPV infection in the past few decades has been called an epidemic.
Who is at risk?
Cancer of the upper airway, which we call head and neck cancer, affects about 45,000 people per year in the United States, comprising 3% of all cancers. Approximately 8,000 people will die from it in the US in the next year.
In the 20th century, the vast majority of head and neck cancers were associated with exposures to tobacco and alcohol. This is still true when it comes to cancers arising from certain sub-sites in the head and neck, such as cancer of the larynx (“voice box”). Fortunately, the decrease in smoking over the past decades has lead to an overall decrease in smoking-related cancers.
However, as one might expect, the increase in HPV infection has led to an increase in HPV-associated cancers, especially in the upper throat (oropharynx). Now, about 70-75% of cancers of the oropharynx show HPV infection. Virtually all of these are infected with a high-risk strain.
This shift in the disease process means that different people are getting head and neck cancer than used to in the past. The most common patient with oropharynx cancer is now a non-smoking, non-drinking middle aged white man.
What does this mean?
A change in the cause of head and neck cancer calls for changes in prevention, screening and prognosis.
Part of prevention of HPV-associated head and neck cancer involves educating people about the risk of the virus and also how one gets it. HPV is sexually transmitted, and the risk of HPV-associated oropharynx cancer is directly increased by the number of oral sex partners that a person has in his lifetime. Limiting risk may include changing peoples’ behavior.
Another critical part of prevention involves the HPV vaccine. The most common brand of this vaccine is known as Gardasil; it prevents infection by “high-risk” cancer-causing strains of HPV. Receiving this vaccine will almost eliminate a patient’s risk of HPV-associated cancers, including cervical cancer and oropharynx cancer. It is now being offered to adolescents in an effort to decrease these cancers in the future.
Our screening criteria also needs to change. Because most oropharynx cancer patients are nonsmokers, doctors and dentists need to be more aware to look for signs of cancer in non-smokers. People also need to pay attention to signs of head and neck cancer in themselves, even if they never smoked. Some of these signs would be a persistent lump in the neck, a funny-looking rough-surfaced sore/lesion in the throat, or a tonsil that was much bigger than the other one.
Researchers are working on a Pap-smear type test to screen for oral HPV infection but so far this is not routinely available.
Prognosis for HPV-associated cancers is also different. HPV-associated oropharynx cancer is treated similarly to non-HPV oropharynx cancer—usually with surgery, radiation or a combination of both. The good news is that HPV-associated cancer has a better response to treatment than smoking-related cancers, resulting in higher cure rates. 3-year disease-free survival with HPV- associated oropharynx cancer is as high as 90%.
What if I am worried about HPV?
Your BergerHenry ENT doctor can screen you for signs of head and neck cancer with a thorough physical exam and biopsy any area that appears concerning. But also remember that most HPV infections are asymptomatic, and most papillomas are benign.
The “New” Head and Neck Cancer Patient- young, nonsmoking, nondrinking and HPV positive. Otolaryngology Head and Neck Surgery, 2014. Vol 151 (3): 375
The New Face of Head and Neck Cancer; the HPV epidemic. Oncology, 2015. Vol 29 (9): 616
The Growing Epidemic of HPV Positive Oropharyngeal Carcinoma. Journal of the American Board of Family Medicine, 2015. Vol 28 (4): 498
Marta T. Becker, M.D.
Alan S. Berger, M.D.