Expression Of PD-L1 And P16 In Oral And Oropharyngeal Squamous Cell Carcinoma And Its Clinical Significance

OBJECTIVE: In recent years,human papillomavirus(HPV)has shown to be closely related to head and neck squamous cell carcinomas(HNSCC).There is relativity between P16 protein and human papillomavirus infection.P16 protein is a stable and reliable alternative indicator of HPV.There is high degree of immunosuppression in head and neck squamous cell carcinoma,which has been considered as immunosuppressive disease.The expression of programmed cell death ligand 1(PD-L1)on the surface of tumor cells is considered as an underlying pathway.Through detecting PD-L1 and P16 in oropharyngeal and oral squamous cell carcinoma and explore the clinical significance and prognosis of PD-L1 and P16 in patients with oropharyngeal and oral squamous cell carcinoma.METHODS: Thirty-nine patients with oropharyngeal and oral squamous cell carcinoma who underwent surgery from February 2012 to March 2016 at the Second Affiliated Hospital of Dalian Medical University were enrolled in this study.P16 and PD-L1 were detected by immunohistochemistry.The relationship between PD-L1 and P16 protein was analyzed by statistics.The dates such as age,smoking history,history of drinking,staging and lymph node metastasis are collected to be analyzed to show the influence on the PFS in patients with squamous cell carcinoma.RESULTS:Of the 39 patients,74.4% have positive PD-L1 expression,the rest results are negative..there is 12 patients(30.8%)of PD-L1(+)and 5 patients(12.8%)of PD-L1(++)and 12 patients(30.8%)of PD-L1(+++).59.0% of the patients have positive expression of P16.41.0% have negative expression.there is 21 patients have positive PD-L1 among the 23 patients who have positive P16 expression.It accounts for 91.3%.In contrast,there are only 8 patients who have positive PD-L1 among the 16 negative P16 expression of patients.The expression rates of PD-L1 in both groups of the patients were 91.3% and 50.0%,respectively.There is significant difference between the two groups(P <0.05).The expression of PD-L1 is significantly correlated with lymph node metastasis(P=0.001)and P16 is correlated with lymph node metastasis(P=0.032).but there is no significant difference in age,sex,smoking,alcohol consumption,T stage,AJCC stage,differentiation degree,primary tumor site and treatment regimen(P?0.05)of PD-L1 and P16.The median PFS of the 39 patients are 23.17 months,and the median PFS of positive PD-L1 expression of patients are 23.38 months,the median PFS of negative PD-L1 expression of patients are 19.75 month.There is no significant difference in PD-L1 and P16(P?0.05).The median PFS of the patients owned the coexpression of positive PD-L1 and positive P16 are 23.20 months.the median PFS of positive PD-L1 and negative P16 expression of the patients are 17.00 months,the median PFS of negative PD-L1 and positive P16 expression of the patients are 40 months,the median PFS of negative PD-L1 and negative P16 expression of the patients are 19.33 months,as result,there is no significant difference(P?0.05).Conclusion:1.PD-L1 is high-expression in oropharyngeal and oral squamous cell carcinoma,and related to P16 expression and lymph node metastasis and no correlation with PFS.2.PD-L1 is high-expression in oropharyngeal and oral squamous cell carcinoma,and related to P16 expression and lymph node metastasis and no correlation with PFS.3.The expression of PD-L1 in oropharyngeal and oral squamous cell carcinoma is related to the infection of HPV.HPV-positive patients with PD-L1 expression is significantly higher than HPV-negative patients.4.The co-expression of PD-L1 and P16 in oropharyngeal and oral squamous cell carcinoma isn?t related to prognosis.