Programmed Death Ligand-1 Expression And Its Prognostic Role In Thoracicesophageal Squamous Cell Carcinoma

ObjectiveTo detecte the expression of PD-L1 in the thoracic esophageal squamous cell carcinoma(ESCC)by immunohistochemistry,and analyze the relationship between the expression of PD-L1 and the clinicopathological features or survival of patients with thoracic ESCC.Determined the independent prognostic significance of the expression of PD-L1 in the primary thoracic ESCC.Materials and methodsIn our hospital surgical oncology,clinical data of 369 patients with esophageal carcinoma patients from January 2007 to July 2011 were Collected,randomly selected 50 patients from the follow-up information completed 104 patients as research crowd,10 patients randomly selected from study group as control group.Then detected the expression of PD-L1 in fetched paraffin specimens by immunohistochemistry.ResultsOf the 50 patients,27 patients were PD-L1 positive(54%),23 patients were negative(46%).Of the 10 patients,1 patientswere low expressed PD-L1 in para-carcinoma tissues(10%).There was no significant difference between the expression of PD-L1 and the clinicopathological features(age,sex,ethnicity,history of smoking,history of alcohol consumption,body weight index,accompanying diseases(hypertension,coronary heart disease,diabetes mellitus)?number of lymph node dissection,tumor location,surgical anastomosis,tumor size,histological differentiation,depth of tumor invasion,lymph node status,postoperative pathological staging,postoperative adjuvant therapy(radiotherapy and chemotherapy))of the patients(P> 0.05).The 5-year survival rate was 22.2%(6/27)of the PD-L1 positive group and 47.8%(11/23)of the negative group,it had significant difference between the groups(P <0.05),the 5-year survival of PD-L1 positive group was shorter than the negative group.Univariate analysis showed,tumor depth(T1 / T2 vs T3 / T4),lymph node status,postoperative pathological stage(stage?/?vs stage?)and the expression of PD-L1(PD-L1 positive vs PD-L1 negative)were statistically significant(P<0.05).Multivariate analysis showed that the expression of PD-L1 was an independent predictor of prognosis in patients with thoracic ESCC(HR = 2.845,95% CI: 1.300-6.226,P = 0.009).ConclusionPD-L1 was highly expressed in tumor tissues of patients with thoracic ESCC,low expressed in the para-carcinoma tissues.There was no relationship between the expression of PD-L1 and the clinicopathological features.Tumor infiltration depth,lymph node status,postoperative pathological stage,PD-L1 expression were important factors of the prognosis.PD-L1 overexpression is associated with poor prognosis,suggesting that PD-L1 is an independent predictor of poor prognosis of patients with thoracic ESCC.