目的：探讨PD-1 和PD-L1 蛋白在胃癌（gastric cancer, GC）组织中的表达及其临床意义。方法：收集河北医科大学第四医院2007 年1 月至2007 年12 月82 例GC患者术后癌石蜡组织标本及其对应的临床病例资料，随访其生存状况。采用免疫组织化学法检测肿瘤组织中PD-1 和PD-L1 蛋白的表达情况，采用Kaplan-Meier 法及Log-Rank检验分析其生存数据，并绘制生存曲线。结果：GC组织中PD-1 蛋白表达阳性率为13.41%，PD-L1 蛋白表达阳性率为42.68%；术前无远处转移患者GC组织中PD-1、PD-L1 及癌间质中PD-L1 表达阳性率明显低于术前有远处转移（PD-1：3.28% vs 42.86%；PD-L1：13.11% vs 90.48%；癌间质中PD-L1：13.11% vs 47.62%，均P<0.01）。胃的切除范围、PD-L1 蛋白过表达及术前有无远处转移是影响GC患者预后的不良因素（P<0.05）。结论：GC组织中PD-1 和PD-L1 蛋白的表达与患者术前有无远处转移和肿瘤的浸润深度密切相关，PD-L1 阳性表达者较阴性表达者术后生存时间短。

Objective: To investigate the expression and clinical significance of PD-1/PD-L1 in gastric cancer (GC) tissues. Methods:Paraffin embedded tumor tissues and clinical data of 82 GC patients who had undergone operation at the Fourth Hospital of Hebei Medical University from January 2007 to December 2007 were collected, and their survival status was followed. The protein expressions of PD-1 and PD-L1 in tumor tissues were detected by immunohistochemistry. Kaplan-Meier analysis and Log-Rank test were adopted to analyze the survival of GC patients, and the ROC curve was plotted. Results: The positive rate of PD- L1 protein expression was 42.68% while the positive rate of PD-1 expression was 13.41% in GC tissues. The positive rate of PD-1 and PD-L1 expression in GC tissues of patients without pre-operative distant metastasis was significantly lower than those patients with pre-operative metastasis (PD-1：3.28% vs 42.86%; PD-L1：13.11% vs 90.48%; all P<0.01). The positive rate of PD-L1 expression in tumor stroma of patients without pre-operative distant metastasis was significantly lower than those with metastasis (PD-L1: 13.11% vs 47.62%, P<0.01). The resection range of stomach, PD-L1 over-expression and the presence of pre-operative distant metastasis were the adverse factors affecting the prognosis of patients with GC (P<0.05). Conclusion: PD-1 and PD-L1 expressions in GC tissues were closely related to the presence of pre-operative distant metastasis and the depth of tumor infiltration. The postoperative survival of patients who were PD-L1 positive was shorter than the negative ones.

河北省自然基金课题资助项目（No. H2015206461)