Study Population
Data for this analysis was obtained from the [Blinded for peer review], a population-based study in [Blinded for peer review].(14) Eligible cases were diagnosed with their first primary squamous cell carcinoma of the oral cavity, pharynx, and larynx diagnosed between January 1st, 2002 and February 28th, 2006; were ages 20 to 80 years at diagnosis; and resided in [Blinded for peer review]. Case ascertainment relied on rapid identification of newly diagnosed cancer cases through the [Blinded for peer review]. The cancer registrars of 54 hospitals in the study area were contacted monthly to identify potentially eligible cases. Potentially eligible study subjects were mailed a brochure describing the purpose of the study, and upon consent, a study nurse conducted an at-home in-person interview. There were 1381 cases of HNSCC in [Blinded for peer review]. Our present analysis included only tumors that were p16+ and classified as oropharynx cancers (C01.9, C02.4, C05.1, C05.2, C09.0, C09.1, C09.8, C09.9, C10.0–C10.4, C10.8, and C10.9). Samples that failed p16 typing were not included. Staging classification was based on the American Joint Commission on Cancer (AJCC) 8th edition. This study was approved by the Institutional Review Board at [Blinded for peer review].