The increasing incidence of oropharyngeal cancers in the United States since 1984 is associated with human papillomavirus, according to research presented recently at the 2011 American Society of Clinical Oncology Annual Meeting in Chicago.

HPV prevalence in 271 oropharyngeal cancer cases, documented in population-based registries, grew significantly during the study period (1984-2004), the researchers found. Compared to HPV-negative cases, median survival was greater for HPV-positive cases and grew significantly over time. This was not true for HPV-negative cases, however.

Population-level incidence of HPV-positive oropharyngeal cancers grew 225 percent during 1988-2004 (0.8/100,000 to 2.6/100,000). If the trend were to continue, HPV-positive cases would double from 4,000-4,500 in 2004 to 8,500 by 2020, researchers reported, with the increase occurring mainly in men.

"You don't want them waking up in 20 or 30 years and finding out they have stage 4 throat cancer. That's where I am now," said Philip Keane, referring to his diagnosis, which prompted the decision to have his 12-year-old son vaccinated against HPV. While the vaccine Gardasil has not been approved to protect against oral HPV cancers, many experts say it likely confers some protection since it targets some of the same HPV strains implicated in these cancers.

As for adults, the growing numbers of HPV-related throat cancers "emphasize the need for head and neck screening even in patients without traditional risk factors of tobacco and alcohol use," said Dr. Chris Sullivan, assistant professor of otolaryngology at Wake Forest Baptist Medical Center. Sullivan was not affiliated with the report.

The study, "Human Papillomavirus (HPV) and Rising Oropharyngeal Cancer Incidence and Survival in the United States," was published in Journal of Clinical Oncology (2011;15:abstract 5529).