Oral Cavity and Oropharyngeal Cancer: Changing Trends in Incidence in the United States and Oklahoma.

Oral cavity cancer (OC) has steadily decreased in the United States (US) since 1973 whereas oropharyngeal cancer (OP) has increased. We analyzed OC and OP cases from the Oklahoma Central Cancer Registry and Surveillance, Epidemiology, and End Results program comparing those diagnosed from 1997-1999 to those diagnosed from 2010-2012. We compared the incidence of OC and OP cases between Oklahoma and the US and by demographic factors. We observed an increase in OP cases, but no change in OC cases in both the US and in Oklahoma, and observed some differences between Oklahoma and the US by race, gender, and age group. A possible explanation for the increasing incidence of OP cancers may be the increasing prevalence of HPV. This study highlighted the differences in temporal trends of OC and OP cancers and the importance of changing risk factors for these cancers.