Human papillomavirus in oropharyngeal squamous cell carcinomas in Korea: use of G1 cycle markers as new prognosticators.

Abstract

Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (SCC) exhibits distinct patterns worldwide, but its prevalence has not been extensively evaluated in Korea. The E7 oncogene-mediated carcinogenesis and its meaning are yet to be uncovered for oropharyngeal SCCs. In a Korean oropharyngeal SCC cohort, epidemiological indicators, HPV, and G1 cell cycle marker expressions were correlated with survival. Among 93 surgically treated patients with oropharyngeal SCCs, 49.5% were HPV+, which were significantly younger, and predominantly nonsmoking. They demonstrated better survival than HPV- (94% vs 60%). Patients who were HPV+ with oropharyngeal SCCs expressed higher p16, cyclin-dependent kinase 4 (cdk4), and lower pRb. The p16 (hazard ratio [HR] 2.39), pRb (HR 2.13), and CCND1 (HR 2.09) correlated with survival. Notably, combined markers like p16/cdk4 ratio (HR 2.47) and cdk4+CCND1 sum (HR 2.65) were more significantly correlated. Incidence of HPV-related oropharyngeal SCC in Korea is similar to U.S.-European data. HPV presence correlates with improved survival. Expression ratios of G1 markers may predict survival of oropharyngeal SCCs better than each marker alone.