New research ties tobacco use to higher risk of oral HPV infection

October 23, 2014

BALTIMORE, USA: A recently published study has shown that infection with the oral human papillomavirus Type 16 (HPV 16), which is also thought to cause oropharyngeal cancer, is more common among people who have recently used or been exposed to tobacco. The researchers found that even modest tobacco use, like three cigarettes per day, is associated with higher oral HPV prevalence. The study included 6,887 participants, who were originally enrolled in the National Health and Nutrition Examination Survey, a program of studies designed to assess the health and nutritional status of adults and children in the U.S. Current tobacco users accounted for 28.6 percent (2,012) of the study population and 1 percent (63) were infected with HPV 16. Examination of blood and urine, as well as oral rinsing and gargling to collect mouth and throat cells, found that participants with higher levels of tobacco-related biomarkers in their blood and urine, which can come from any tobacco source—even secondhand smoke—were more likely to have oral HPV 16 DNA compared with those who had no detectable levels of the compounds, explained Dr. Carole Fakhry, an assistant professor of otolaryngology–head and neck surgery at the Johns Hopkins University School of Medicine, where the study was conducted. According to the study, oral HPV 16 prevalence was greater in current tobacco users (2.0 percent) than in former tobacco users or those who had never consumed tobacco (0.6 percent). In addition, a dose–response relation was found. The equivalent of three cigarettes per day increased the risk of HPV 16 by 31 percent, and the equivalent of four cigarettes per day increased the risk by 68 percent. HPV 16 is primarily transmitted through oral sex, and current tobacco users in the study were more likely to have a higher number of lifetime oral sexual partners compared with nonusers. Thus, although the study found an independent relationship between tobacco use and HPV 16 infection, it cannot be ruled out that participants who used more tobacco might also have had more oral sex and were therefore at higher risk of infection. The study, titled “Tobacco Use and Oral HPV-16 Infection,” was published in the Oct. 8 issue of the Journal of the American Medical Association.