Human papillomavirus (HPV) is the leading cause of cervical cancer, and the high-risk type known as HPV-16 is an established cause of oropharynx cancer, an uncommon type of head and neck cancer that is on the rise in men in the US. New research published in JAMA Oncology suggests that other types of HPV may also be associated with an increased risk of head and neck squamous cell carcinoma (HNSCC) – cancers that develop in the mouth (oral cavity), the part of the throat just behind the mouth (oropharynx), and/or a lower part of the throat that includes the vocal cords (larynx).
There are more than 150 types of HPV, several of which can be present in the oral cavity. This study examined associations between several different types of HPV and the risk of HNSCC, using data from the American Cancer Society’s Cancer Prevention Study-II Nutrition Cohort and the National Cancer Institute’s Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial.
Among 96,650 people who were cancer-free at the start of the study, 132 (103 men and 29 women) developed HNSCC. The researchers found that the presence of oral HPV-16, a type of the virus that causes cervical cancer and other anogenital cancers in men and women, increased risk of cancer of the oropharynx 22-fold when compared to people without oral HPV. This increased risk of cancer was specific to the oropharynx; oral HPV-16 infection was not associated with cancers of the oral cavity or the larynx.
A range of other HPV types were also detected in the oral cavity and found to be associated with head and neck cancers, some more strongly than others, explains study co-author Susan Gapstur, PhD, MPH, vice president of the epidemiology research program at the American Cancer Society.
“The results of our study are consistent with findings from other studies demonstrating that HPV-16 is a cause of oropharynx cancer, and extends those findings by showing that oral HPV-16 infection precedes cancer development by many years,” Gapstur says. “The study also demonstrated for the first time that other HPV types might be associated with cancer risk. However, these findings should be interpreted cautiously and need replication in larger studies.”
Over the past 3 decades, there has been a drop in the incidence of head and neck cancers caused by tobacco and alcohol, and a rise in the incidence of head and neck cancers caused by HPV, according to a study published in Oral Oncology in 2015. The reason for a rapid rise in HPV-positive cancer of the oropharynx is not totally clear, but it is likely related to changes in sexual behavior in recent decades, including oral sex becoming more common.
“Increasing education about the role of HPV infection as a cause of several types of cancer, along with increasing HPV vaccination rates, may help to prevent multiple HPV-related cancers in future generations,” Gapstur says.
In addition to Gapstur, two other American Cancer Society researchers were among the authors of the JAMA Oncology study: Lauren Teras, PhD, director of hematologic cancer research, and epidemiologist Rebecca Anderson, MPH.