Expression Of PD-L1 In CcRCC And Its Clinical Significance

Background:The study found that the progression of renal cell carcinoma(RCC)has an important relationship with the immune evasion mechanism of tumor cells.Among them,programmed cell death legend 1(PD-L1/CD274)plays an important role in the immune escape mechanism of tumors.PD-L1 is closely related to the prognosis of tumors,but the study of PD-L1 in the prognosis of patients with renal cell carcinoma is rare,and there is no consistent conclusion.This topic discusses the expression of PD-L1 in ccRCC tissue and the significance of PD-L1 in clinical,pathological features and prognosis.Objective:To investigate the expression of PD-L1 in ccRCC tissues and its value in clinical,pathological features and prognosis evaluation.Materials and Methods:From July 2017 to November 2017,10 cases of cancer tissue and 10 cases of adjacent cancer tissues of ccRCC patients were collected and stored frozen.Western-blot was used to analyze the expression of PD-L1 in cancer tissues and adjacent tissues.At the same time,181 cases of ccRCC hospitalized from January 2010 to January 2018 were collected.Immunohistochemical staining was used to retrospectively analyze the expression of PD-L1 in cancer tissues and its correlation with clinical,pathological features and prognosis of ccRCC.Data from the database(CCLE,GEO database,Japan Cohort)were studied to investigate the expression of PD-L1 in cancer tissues and its relationship with clinical,pathological features,and prognosis of ccRCC.Results:The expression of PD-L1 in ccRCC tissues was higher than that in paracancerous tissues with statistical difference(P=0.0084).ccRCC tissue have PD-L1 positive expression in 39 cases(39/181,21.5%).Positive expression is associated with tumor size(P=0.001),grade(P<0.001),stage(P=0.002),recurrence(P=0.011),death(P<0.001),regional lymph node metastasis(P=0.001)and necrosis(P= 0.013).PD-L1 positive expression was lower in PFS(P=0.015)and OS(P<0.001)than in PD-L1-negative patients.Univariate analysis revealed that grading(P=0.018),staging(P<0.001),and PD-L1 expression(P=0.001)were all independent predictors of ccRCC.Multivariate analysis revealed thatPD-L1(P=0.006)was an independent prognostic factor for ccRCC.Database studies showed that the expression of PD-L1 mRNA in renal tubular epithelial cells(HK-2)was lower than that in renal cancer cells.The expression of PD-L1 mRNA in ccRCC patients was higher than that in adjacent normal tissues.Patients with high expression of PD-L1 mRMA in ccRCC patients had lower OS than those with low expression.Conclusions:PD-L1 was differentially expressed in tumor and paracancerous tissues.Cancer tissues have higher expression of PD-L1.The expression of PD-L1 was significantly correlated with tumor size,tumor grade,tumor stage,recurrence rate,mortality,local lymph node metastasis,and necrosis of tumors;PD-L1 positive expression was associated with lower PFS and OSin patients.PD-L1 is an independent risk factor for the patient's OS.PD-L1 plays an important role in the occurrence and development of renal cell carcinoma,and can provide guidance for targeted drug therapy and prognosis of renal cell carcinoma.