Independent association of marijuana use and poor oral hygiene with HPV–negative but not HPV–positive head and neck squamous cell carcinomas

Background: Sexual behavior is associated with human papillomavirus (HPV)–positive head and neck cancer, whereas tobacco and alcohol use are associated with HPV–negative cancer. A case-control study was designed to investigate additional demographic and behavioral factors independently associated with these distinct oral cancers. Methods: From 2011 to 2014, 249 newly diagnosed oral cavity and oropharyngeal squamous cell carcinoma (OSCC) cases were matched (1:2) on age, gender, and self-identified race to 498 controls without a cancer history attending the outpatient otolaryngology clinic at The Ohio State University in Columbus. Cases were stratified by detection of high-risk HPV DNA and RNA in tumors. Demographic and behavioral data were collected using an audio computer-assisted self-interview, and associations with HPV–positive versus HPV–negative OSCCs were investigated by use of univariable and multivariable conditional logistic regression models. Results: After adjustment for oral sexual behavior, the odds of HPV–positive cancer decreased with the patient's years of education. Annual income, tobacco smoking, alcohol drinking, marijuana smoking, and poor oral hygiene were not associated with HPV–positive OSCC. In contrast, the odds of HPV–negative OSCC increased independently with decreased annual income, decreased with a high number of marijuana hit-years, and increased with fewer than annual dental visits after adjustment for lifetime tobacco and alcohol use. Sexual behavior and education were not associated with HPV–negative OSCC. Conclusions: The distinct risk-factor profiles for HPV–positive and HPV–negative OSCC are confirmed and extended in this case-control study, thus supporting 2 principal etiological pathways for OSCC development. Lay Summary: Sexually acquired human papillomavirus (HPV) infection is an established cause of tonsil and base of tongue cancers. This study compared and contrasted risk factors for HPV–positive and HPV–negative oral cancers. Low number of years of education and sexual behavior are associated with HPV–positive cancer. In contrast, low annual income, infrequent dental visits, and tobacco and alcohol use are associated with HPV–negative cancers. Long-term marijuana use appears protective for HPV–negative cancer. Public health efforts to address these modifiable risk factors may prevent oral cancer.