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].