Human papillomavirus (HPV) in Chinese oropharyngeal squamous cell carcinoma (OPSCC): A strong predilection for the tonsil.

Objective: Compared with Occident's data, the incidence of Human papillomavirus (HPV)-driven oropharyngeal squamous cell carcinomas (OPSCCs) had been reported as relatively low in Mainland China. The objective of this study was to report the integrated prevalence of HPV and Epstein-Barr virus (EBV), and further evaluate the different behaviors of HPV-positive and -negative OPSCCs in eastern China.

Methods: In a cohort of 170 nonmetastatic OPSCCs treated from January 2007 to July 2019, p16 protein expression, HPV genotypes, and Epstein-Barr virus-encoded RNA (EBER) were determined by immunohistochemistry (IHC) and in situ hybridization (ISH). The clinical and pathologic findings were further collected and analyzed to comprehensively reveal the behaviors of Chinese OPSCCs.

Results: Out of the 170 tumor tissues evaluated, 57.6% (98) samples had positive p16 expressions. A total of 65.1% (99/152) samples had positive HPV genotypes, besides HPV16 (92/152), HPV11, 18, 33, 53, and 58 were also detected. The positive rate of EBER was 7.2% (9/124), and the co-infection rate of EBV/HPV was 4.0%. Related to the unequal distributions of p16 expression, HPV-related tumors arisen from tonsillar and non-tonsillar accounted for 68.8% (75/109) and 37.7% (23/61) of their cases, respectively (P < .001). With a median follow-up time of 13.1 months, significant survival advantages of HPV-related OSPCC were observed; 1-year OS, PFS, RFS, and MFS were 83.2% vs 96.7% (P < .001), 71.6% vs 96.2% (P < .001), 77.7% vs 96.2% (P = .002), and 90.4% vs 100.0% (P = .024) in p16-negative and -positive cases, respectively.

Conclusions: The relative percent of HPV-positive OPSCCs in this study is close to the positive rate in many Western countries and a strong predilection was discovered for the tonsillar. The EBV infection and co-infection of HPV/EBV were largely low. The prognosis of HPV-positive OSPCCs was more favorable than its negative counterpart.