左、右半结肠癌PD-L1表达、MSI状态、KRAS突变及临床病理特征的差异

Differences of PD-L1 expression,MSI status,KRAS mutation,and clinicopathological characteristics between left and right colorectal cancer

目的:探讨左半结肠癌、右半结肠癌程序性死亡因子配体1(programmed death-ligand 1,PD-L1)表达、微卫星不稳定性(microsatellite instability,MSI)、Kirsten大鼠肉瘤病毒癌基因同源物(Kirsten rat sarcoma viral oncogene homolog,KRAS)基因突变以及临床病理特征的差异。方法:收集2021年1月至12月郑州大学附属肿瘤医院临床病理中心723例结直肠癌患者的临床病理与分子检测资料进行回顾性分析;采用聚合酶链反应(polymerase chain reaction,PCR)法检测MSI、KRAS基因突变,免疫组织化学法评估PD-L1蛋白表达。结果:在723例结直肠癌中,左半结肠癌521例,右半结肠癌202例。相较于左半结肠癌,右半结肠癌具有女性多发、浸润深度更深、分化更差的特点(均P<0.05);同时,右半结肠癌MSI发生率显著高于左半结肠癌(P<0.001),且PD-L1的联合阳性分数也显著高于左半结肠癌(P=0.022)。此外,左、右半结肠癌在年龄、淋巴转移、脉管癌栓、神经侵犯和KRAS基因突变等方面差异均无统计学意义(均P>0.05)。结论:左半结肠癌、右半结肠癌的临床病理特征、MSI状态及PD-L1表达均存在显著差异,提示左、右半结肠癌可能是两种不同的肿瘤。

Objective:To investigate the differences of programmed death-ligand 1(PD-L1)expression,microsatellite instability(MSI),Kirsten rat sarcoma viral oncogene homolog(KRAS)gene mutation,and clinicopathological characteristics between left and right colorectal cancer.Methods:A total of 723 colorectal cancer patients with complete clinicopathological and molecular detection data from January to December 2021 were selected from the Clinical Pathology Center of Affiliated Cancer Hospital of Zhengzhou University for retrospective analysis.Polymerase chain reaction(PCR)was used to detect MSI and KRAS gene mutations,and immunohistochemistry was used to evaluate the expression of PD-L1 protein.Results:Among the 723 cases of colorectal cancer,there were 521 cases of left colorectal cancer,and 202 cases of right colorectal cancer.Compared with left colorectal cancer,the right colorectal cancer occurred more often in women,with deeper invasion depth and worse differentiation(all P<0.05).Moreover,the incidence of MSI in right colorectal cancer was significantly higher than that in left colorectal cancer(P<0.001),and the combined positive score of PD-L1 was also significantly higher than that in left colorectal cancer(P=0.022).Besides,there were no significant differences in age,lymphatic metastases,vascular carcinoma embolism,nerve invasion and KRAS gene mutation between left and right colorectal cancer(all P>0.05).Conclusion:There are significant differences in the clinicopathological characteristics,MSI status,and PD-L1 expression between left and right colorectal cancer,suggesting that left and right colorectal cancer may be 2 different tumors.