New understanding of oral HPV infections in healthy men
Scientists report that newly acquired oral HPV infections in healthy men are uncommon and, when present, tend to go away within one year. HPV infection is known to cause virtually all cervical cancers, along with some genital and anal cancers. It has recently been established as a cause of the majority of oropharyngeal cancers, a malignancy of the upper part of the throat. Aimée R. Kreimer, Ph.D., Division of Cancer Epidemiology and Genetics, NCI, and her collaborators at the Moffitt Cancer Center, Tampa, also determined that acquisition of oral HPV appeared more common among smokers and unmarried men. Their study appeared in Lancet July 2, 2013.
Oropharyngeal cancer is rare, but rates have been increasing rapidly, especially among men. The natural history of HPV infection in the oral region among healthy people has not been described. To determine the pattern of acquisition and persistence, the researchers evaluated the HPV infection status in oral gargle samples collected from more than 1,600 men in Brazil, Mexico, and the United States as part of the HPV Infection in Men (HIM) study. Over a 12-month period, 4.4 percent of participants acquired an oral HPV infection (which includes all types of HPV), 1.7 percent were infected with a cancer-causing HPV type, and 0.6 percent with HPV16, the HPV type responsible for the majority of HPV-related oropharyngeal cancers. These observed rates are considerably lower than cervical and other genital tract HPV infections among healthy individuals. The age pattern was also different -- oral HPV infections were acquired across the age range in the study, while cervical HPV infections typically peak shortly after sexual initiation. For men with any new infection, the estimated median time to clearance was 6 months, similar to rates observed at other anatomic sites where HPV causes cancer.