By Alan Mozes
FRIDAY, Jan. 9, 2015 (HealthDay News) -- One type of oral HPV (human papillomavirus) infection, HPV16, seems to last a year or longer in men over the age of 45 than it does in younger men, new research indicates.
HPV16 is the form of HPV often associated with the onset of head and neck cancers (oropharyngeal), the study team noted.
"Oral HPV16 is the HPV type most commonly found in HPV-driven oropharyngeal cancers, which have been increasing in incidence recently in the United States," said study author Christine Pierce Campbell in a American Association for Cancer Research news release. She is an assistant member in the department of Cancer Epidemiology and Center for Infection Research in Cancer at the Moffitt Cancer Center in Tampa, Fla.
"We don't know how long oral HPV infection must persist to increase risk for head and neck cancer," she added, "but we assume it would be similar to cervical infection, where it is generally believed that infections persisting beyond two years greatly increase the risk of developing cervical cancer."
The study was released online on Jan. 9 in Cancer Prevention Research.
The researchers analyzed four years of samples from more than 1,600 men. The samples were collected every six months.
During the study, 23 men had two or more positive oral HPV16 samples. Of these, 10 had HPV16 when the study began.
In the group that had HPV16 at the start of the study, nine had infections that lasted a year or more. Additionally, the researchers found that eight of these infections lasted two years or more, and two lasted four years or more, the researchers found.
In those who developed infections during the study, the team found that infections in men older than 45 all lasted one year or more. By contrast, just half the infections among men 31 to 44 years persisted for one year or longer. And none of the infections detected among men 18 to 31 years lasted for a year, according to the researchers.
"Our results show that some oral HPV16 infections persist in men for four years or more and that persistence seemed to increase with age," Pierce Campbell said.
She also noted that genital HPV infections usually clear up in two years or less. This study's findings suggest that oral infections may be more persistent than genital HPV.