PD-L1在结直肠癌中的表达水平及其诊断和预后价值

Expression of PD-L1 in colorectal cancer and its diagnostic and prognostic value

目的探讨程序性细胞死亡配体l(PD-L1)在结直肠癌中的表达及其诊断和预后价值。方法收集2013年10月至2018年6月期间于湖南中医药大学第一附属医院进行手术治疗的60例结直肠癌患者的癌组织及其对应的癌旁组织标本,采用qRT-PCR方法和免疫组织化学方法分别检测PD-L1 mRNA和蛋白的表达。结果结直肠癌组织中PD-L1 mRNA表达水平(4.69±1.35)显著高于癌旁正常组织(2.43±1.01),差异有统计学意义(P<0.05)。结直肠癌组织中PD-L1蛋白表达水平显著高于癌旁正常组织。结直肠癌组织中PD-L1 mRNA和蛋白表达水平与肿瘤大小、TNM分期、淋巴结转移呈显著相关,差异有统计学意义(P<0.05),而与年龄、性别和肿瘤部位无关,差异无统计学意义(P>0.05)。PD-L1 mRNA表达水平诊断的结直肠癌ROC曲线下的面积为0.908。生存分析显示PD-L1蛋白低表达组患者的中位总体生存时间(>60个月)比PD-L1蛋白高表达组(39个月)长,差异有统计学意义(P<0.05)。结论 PD-L1表达水平与患者肿瘤大小、TNM分期、淋巴结转移、总体生存期相关,是患者预后的重要因素,在结直肠癌的诊断和预后中具有一定的临床价值。

Objective To investigate the expression of programmed cell death ligand 1(PD-L1) in colorectal cancer and evaluate its diagnostic and prognostic value.Methods Cancer tissues and adjacent tissues of 60 patients with colorectal cancer who underwent surgical treatment in The First Hospital of Hunan University of Chinese Medicine from October 2013 to June 2018 were collected.The mRNA and protein expression of PD-L1 were detected by qRT-PC.R and immunohistochemistry,respectively.Results The mRNA expression of PD-L1 in colorectal cancer tissues(4.69±1.35)were significantly higher than that in adjacent tissues(2.43±1.01)(P<0.05).The protein expression levels of PD-L1 in colorectal cancer tissues were also significantly higher than that in adjacent tissues.The PD-L1 mRNA and protein expression levels in colorectal cancer tissues were significantly correlated with tumor size,TNM stage and lymph node metastasis(P<0.05),while had no relationship with age,sex and tumor location(P>0.05).The area under curve was0.908 according to ROC result using PD-L1 mRNA expression level to diagnose the colorectal cancer.Survival analysis showed that the median overall survival time of patients with low PD-L1 protein expression level(>60 months) was longer than that of patients with high PD-L1 protein expression level(39 months)(P<0.05).Conclusions The PD-L1 expression level was correlated with tumor size,TNM stage,lymph node metastasis,and overall survival time of patients with colorectal cancer.PD-L1 could be an important prognostic factor in patients with colorectal cancer.It had a certain clinical value in the diagnosis and prognosis of colorectal cancer.