Prospective Study Strengthens Link Between Oral HPV Infection And Some Head and Neck Cancers

Infection with the hpv-16 strain often precedes certain forms of the disease, researchers say

Issue 27 Summer/Fall 2016

Experts have long suspected that infection with the human papillomavirus (HPV) in the mouth and throat might be a contributing cause of many cases of head and neck cancer.

Now, the first prospective study on the issue - one looking at oral HPV infection before tumor onset - appears to confirm the HPV-16 strain as a culprit in at least some forms of the disease.

HPV is perhaps best known as the cause of cervical cancer. However, there’s a growing body of literature suggesting that infection of the oral cavity might also help spur oropharyngeal tumors - cancers of the tongue, tonsils, soft palate and parts of the throat.

A team led by Dr. Ilir Agalliu of Albert Einstein College of Medicine in New York City sought to confirm this link in the first prospective study on the subject. The researchers looked at data from two major U.S. cancer trials that together included almost 100,000 people. Everyone in the trials was cancer-free at the outset of the studies, and all submitted a special mouthwash sample (containing oral cells) to scientists as they began the research. Over nearly four years of follow-up, 132 people in the trials developed some form of head and neck cancer.

Agalliu’s team compared the mouthwash samples collected from those individuals to samples taken from 396 matched healthy "controls." They also adjusted for other well-known head and neck cancer risk factors, such as smoking and history of alcohol use.

According to the researchers, the presence of one strain of the virus in the mouthwash samples - HPV-16 - was highly correlated to the later development of oropharyngeal tumors. In fact, people whose sample contained HPV 16 were more than 22 times more likely to go on to develop such cancers, compared to people whose sample did not contain the strain, the researchers said.

Speaking in a news release from the U.S. National Cancer Institute (which funded the study), Agalliu said that the findings "provide, for the first time, clear evidence that detection of HPV-16 DNA in the oral cavity precedes the diagnosis of oropharyngeal cancers and confers a substantial risk for these cancers." And what about oral infection with one of the many other strains of HPV? The study also found weaker evidence that the presence in the mouth of so-called "beta-" and "gamma-" strains of HPV - typically found on the skin - was also linked to the later development of head and neck cancers.

Might an oral test for HPV be used someday to predict people’s risk for such cancers? Study co-author Dr. Aimée Kreimer, of the NCI’s Division of Cancer Epidemiology and Genetics, stressed that it’s probably "premature" to offer such a test at this point in time.

Study senior author Dr. Robert Burk, also of the Albert Einstein College of Medicine, agreed that more research is needed.

The factors driving these cancers are complex, he said, and "we need to better understand the role of other risk factors - namely, cigarette smoking and alcohol consumption - and how they interact with oral HPVs in head and neck cancers."

The study was published earlier this year in JAMA Oncology.