Pre-HPV vaccine, most oropharyngeal cancers HPV+

(HealthDay)—Most oropharyngeal cancers in the United States diagnosed between 1995 and 2005 were positive for human papillomavirus (HPV), specifically HPV 16 or 18, according to a study published in the May issue of the U.S. Centers for Disease Control and Prevention's Emerging Infectious Diseases.

To establish a pre-vaccine baseline, Martin Steinau, Ph.D., from the CDC in Atlanta, and colleagues examined the prevalence of HPV types in oropharyngeal cancers in the United States. Patients in whom cancer was diagnosed during 1995 to 2005 had HPV DNA extracted from tumor tissue samples that were obtained from cancer registries and Residual Tissue Repository Program sites. Polymerase chain reaction reverse line blot assays were used to detect and type HPV.

The researchers found that 72 percent of the 557 invasive oropharyngeal squamous cell carcinomas were positive for HPV, and 62 percent were positive for HPV 16 or 18. Lower prevalence of HPV 16/18 was seen for women versus men (53 versus 66 percent) and for non-Hispanic blacks versus other racial/ethnic groups (31 versus 68 to 80 percent).

"Results indicate that vaccines could prevent most oropharyngeal cancers in the United States, but their effect may vary by demographic variables," the authors write.

One author disclosed financial ties to Merck, the manufacturer of the HPV vaccine Gardasil.

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