High risk HPV detection by RNAscope in situ hybridization combined with Cdc2 protein expression by immunohistochemistry for prognosis of oropharyngeal squamous cell carcinoma.

High risk human papillomavirus (HPV) infection is related to the development of head and neck squamous cell carcinoma (HNSCC). Oropharyngeal squamous cell carcinoma (OPSCC) is a common type of HNSCC, and its incidence has increased significantly in recent years. In this study, high risk HPV, the expression of P53, P21, and Cdc2 in OPSCC tissues was detected and the prognostic factors and clinical value of OPSCC were discussed. According to the WHO classification and diagnosis standard for head and neck tumors (2017 Edition), 49 OPSCC cases with complete clinical data were collected from Tangshan Head and Neck Disease Pathology Research Base from January 1, 2012 to December 31, 2018. The E6 and E7 mRNA of HPV 16 and HPV 18 were detected by RNAscope in situ hybridization. The expression of P53, P21, and Cdc2 protein was observed by SP immunohistochemical method and all cases were followed up for survival. Median survival time was analyzed by Kaplan-Meier method. The Log-rank test was used for single factor analysis and Cox regression model was used to analyze multiple prognostic factors. In 49 OPSCC cases the median age was 53 years; 14 were HPV-DNA positive (14/49, 28.6%) while 35 were negative (35/49, 71.4%). E6, E7 mRNA test showed that 20 cases (20/49, 40.8%) were positive for HPV-16. Among them 11 cases were positive for HPV-16 DNA. 2 cases were positive for HPV-18 mRNA (2/49, 4.08%). 27 cases were negative for mRNA16 and 18 (27/49, 55.1%). The prevalence of HPV was 68.8% (11/16) in the non-smoking group, which was higher than that of the smoking group (10/33, 33.3%), (χ2=5.463, P=0.019). There was no significant correlation between HPV detection and gender, age, drinking, tumor differentiation degree, and clinical stage (P > 0.05). The expression rates of P53, P21, and Cdc2 in OPSCC tissues were 63.3% (31/49), 65.3% (32/49), and 67.3% (33/49), respectively. There was no significant correlation between expression of all the three proteins and gender, age, HPV, smoking, drinking, tumor differentiation, and clinical stage (P > 0.05). Cox multifactor regression analysis showed that HPV (HR=0.275, 95% CI: 0.146-0.517), tumor differentiation (HR=1.751, 95% CI: 1.231-2.492), stage (HR=3.268, 95% CI: 1.758-6.074) and expression of Cdc2 protein (HR=1.804, 95% CI: 0.990-3.286) were related to the survival time of patients (P < 0.05). Our findings support that most of the HPV-positive OPSSC patients were non-smokers. The patients with negative HPV, low differentiation, late stage, and Cdc2 positive expression have poor prognosis and need to be followed up.