Oral human papillomavirus infection, sexual behaviors and risk of oral squamous cell carcinoma in southeast of China: A case-control study.

BACKGROUND: The causal association between human papillomavirus (HPV) and oral squamous cell carcinoma (OSCC) remains controversial. Most of previous studies did not consider the potential modification effect of sexual behaviors when evaluating the role of HPV infection in OSCC risk.

OBJECTIVES: To explore the independent and joint effects of oral HPV infection and sexual behaviors on OSCC in Chinese population.

STUDY DESIGN: A case-control study was conducted from September 2012 to September 2015 in Fujian, China. HPV DNA genotypes were detected in tumor tissues of 178 OSCC patients and oral exfoliated cells of 189 frequency-matched controls using flow-through hybridization and gene chip. Epidemiologic data were collected with a structured questionnaire by face-to-face interviews. Odds ratios (ORs) and 95% confidence interval (CI) were estimated with unconditional logistic regression models.

RESULTS: The overall HPV prevalence was 14.04% in OSCC patients and 3.17% in controls. HPV-18 was the most prevalent type in cases and controls (10.67% vs. 2.12%). Oral HPV infection was strongly associated with an increased risk of OSCC: the ORs were 7.21 (95% CI: 2.61-19.88) for HPV16/18 and 7.59 (95% CI: 2.34-24.64) for HPV-18. Moreover, the significant associations were only observed in females, young adults, married population, merchants, non-smokers, non-alcohol drinkers and non-tea drinkers. Additionally, the first intercourse below 22years of age and oral sex practice did not show an association with OSCC. But there was a significantly multiplicative interaction between HPV 16/18 and age at first intercourse for OSCC (Pinteraction <0.001).

CONCLUSIONS: Oral HPV infection (specifically type 18) is an independent risk factor for OSCC in Fujian area. Furthermore, there might be a combined effect of HPV 16/18 and age at first intercourse on OSCC.