The HPV prevalence in oropharyngeal cancer significantly increased across the time period, regardless of the assay used, and remained statistically significant, even after correcting for potential loss in assay sensitivity, Dr. Gillison reported. Genotyping with the Inno-LiPA assay appeared to be the most precise, detecting more than a fourfold increase in HPV prevalence from 16.3% in 1984-1989 to 72.7% in 2000-2004.
Median survival was significantly better for patients with HPV-positive cancer at 131 months vs. 20 months for HPV-negative patients (log rank P value less than .001). HPV-positive cases on all assays had a significant reduction in hazard of death compared with HPV-negative cases after adjustment for age, sex, race, registry, calendar period, stage, surgery, chemotherapy, and radiotherapy.
Survival of HPV-positive cases increased over the study period but remained unchanged for HPV-negative cases. Consequently, survival of all oropharyngeal cancer cases improved over time, according to the results of the study, which was led by Dr. Amil Chaturvedi, an investigator with the division of cancer epidemiology and genetics at the National Cancer Institute, Rockville, Md.
Dr. Gillison and Dr. Chaturvedi reported no conflicts of interest. A coauthor disclosed consultancy, research funding, and honoraria from Merck.