Oral Cancer and HPV
If you have heard of human papillomavirus (HPV), you may know it’s a very common sexually transmitted infection. The virus most often infects moist surfaces, such as the mouth, cervix and vagina.
According to the Centers for Disease Control and Prevention, HPV is so prevalent that most sexually active adults will contract at least one strain of HPV in their lifetime. In many instances, HPV will not cause any symptoms, while in other cases, it may lead to genital warts.
Raising the most concern, however, is the fact that some strains or subtypes of HPV are linked to certain types of cancer — including cervical and oral cancer.
Oral Cancer Associated With HPV
Oral cancers associated with HPV occur in the back of the throat or oropharynx, including at the base of the tongue and in the tonsils. Symptoms may include:
- A sore that doesn’t go away;
- Difficulty or pain in swallowing;
- Ear pain; and
- The feeling of a lump in the neck.
Tumor types can vary. “There are different types of oral cancer tumors, but the most common tumor is squamous cell carcinoma, which accounts for about 90 percent of oral cancers,” said Lanceford Chong, MD, medical director of Western Regional Medical Center, Cancer Treatment Centers of America.
Smoking and chewing tobacco products, heavy alcohol consumption and infection with HPV are all risk factors for oropharyngeal cancer. Treatment depends on the stage at which the cancer is caught and usually involves surgery and radiation therapy. In some cases, chemotherapy may also be used.
Rising Oral Cancer Rates in Young Adults
In the past, oral cancer typically affected adults ages 50 to 60 with a smoking history. But statistics are changing, with a rise in younger people being diagnosed. According to the Oral Cancer Foundation, the fastest growing population developing certain types of oral cancer are nonsmokers between the ages of 25 and 50 years old.
What’s more, a smoking history is no longer the only principal suspected cause. “This increase is thought to be related to HPV16 infection, rather than smoking or other risk factors,” says Chong. “Some researchers anticipate an epidemic of HPV-related oral cancer in the next decade."
HPV-related oral cancer appears to be mostly found in the back of the tongue and the throat.
How HPV and Cancer are Linked
There are many different strains of HPV. Some subtypes of HPV are considered to be low risk for causing illness. But about 15 types are considered to be related to cancer, especially the virus known as HPV16.
The same strains of the virus that infect the genital tract can also infect the oral cavity and throat. “Some oral neoplasms are associated with the same subtype of HPV, which also can cause cervical cancer,” says Guiseppe Del Priore, MD, national director of gynecologic oncology and southeastern regional director at Cancer Treatment Centers of America.
When the oral cavity becomes infected with HPV through sexual activity, the infection can cause changes to the DNA of the cells. In many cases, the body fights off the infection, and the immune system repairs the damaged cells. But in some instances, the changes continue, and the cells grow out of control. Then, tumor growth may develop.
Some factors regarding HPV and oral cancer are not fully understood. For example, in general, HPV positive oral cancer often has a better five year survival rate than HPV negative oral cancer, according to Mount Sinai Hospital.
“It is not entirely clear why HPV related oral cancers are sometimes associated with better outcomes. Theories include that these cancers are more sensitive to current treatments and that they are naturally a slower growing cancer,” says Del Priore.
Know your risks:
- HPV can spread even when there are no symptoms, and the infected person is unaware of infection.
- Currently available HPV vaccines were not designed to protect against oral cancers, and experts don’t know whether they do protect against oral cancer. While genital HPV screening is available, there is not yet a test for oral HPV.
- If you are a heavy drinker or smoker, consider giving up these habits. Get help if needed, as many oral cancers are attributed to these risk factors.
- Be sure to have your doctor or dentist check out any unusual sores that don’t heal or any chronic symptoms, such as a sore throat or a cough that doesn't go away.
Chong L., MD, medical director of Western Regional Medical Center at Cancer Treatment Centers of America. http://www.cancercenter.com/western/doctors-and-clinicians/lanceford-chong/. Interviewed April 2014.
Del Priore G., MD, national director of gynecologic oncology and southeastern regional director at Cancer Treatment Centers of America. http://www.cancercenter.com/southeastern/doctors-and-clinicians/giuseppe-del-priore/. Interviewed April 2014.
Centers for Disease Control and Prevention. “Genital HPV Infection Fact Sheet.” Updated March 2014. http://www.cdc.gov/std/HPV/STDFact-HPV.htm#a5. Accessed April 2014.
Oral Cancer Foundation. “HPV/Oral Cancer Facts.” http://www.oralcancerfoundation.org/hpv/hpv-oral-cancer-facts.php. Accessed April 2014.
Mount Sinai Hospital. “Human HPV and Throat/Oral Cancer Frequently Asked Question.” http://www.mountsinai.org/patient-care/service-areas/ent/areas-of-care/head-and-neck-cancer/oral-cancer/hpv/hpv-faq. Accessed April 2014.