Background: The treatment mode of lung cancer is epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) as a first-line treatment for patients with EGFR mutant in non-small cell lung cancer (NSCLC). At the same time programmed death receptor 1 (PD-1) and its programmed death receptor ligand 1 (PD-L1) inhibitors therapy as the representative immune checkpoint inhibitors (ICIs) has a significant effect in the treatment of lung cancer. The aim of this study was to investigate the correlation between the expression of PD-1 and PD-L1 in NSCLC and clinicopathologic feature, EGFR gene mutation.
Methods: The protein expression of PD-1 and PD-L1 was detected by immunohistochemistry from 127 patients with NSCLC and EGFR gene mutation was detected by quantitative polymerase chain reaction (qPCR) to analyze its relation with clinicopathologic feature. Also, the correlation between protein expression of PD-1 and PD-L1 and EGFR mutation.
Results: The PD-1 positive expression in NSCLC tumor cells and tumor infiltrating immune cells is 53.5% (68/127), PD-L1 is 57.5% (73/127). The PD-1 and PD-L1 expression significantly higher in well-differentiated and moderately-differentiated carcinoma than poorly differentiated carcinoma, I+II than III+IV in clinical staging (P<0.05). The EGFR mutation rate was 46.5% (59/127), correlate with female, without smoking history, adenocarcinoma and well-differentiated and moderately-differentiated patients respectively higher than male, smoking history, squamous carcinoma and poorly differentiated patients (P<0.05). The protein expression of PD-L1 and PD-1 had the consistency in NSCLC patients (kappa=0.107,5, P=0.487). There was a negative correlation between the EGFR mutation and PD-1 and PD-L1 expression (Φ=-0.209, Φ=-0.221, P<0.05). Follow-up of NSCLC patients, the median total survival in under the age of 65, adenocarcinoma, well-differentiated and moderately-differentiated, with PD-L1 expression patients respectively higher than over the age of 65, squamous carcinoma, poorly differentiated, without PD-L1 expression patients (P<0.05). The median survival of hypo expression patients of PD-L1 significantly higher than hyper expression patient (P=0.04).
Conclusions: According to the Chinese Expert Consensus on Standards of PD-L1 immunohistochemistry testing for NSCLC, we tested the PD-L1 expression in NSCLC and then the dominant population of anti-PD-1/PD-L1 treatment was screened out. Patients with EGFR mutation were also detected and EGFR mutation was negatively correlated with the expression of PD-1 and PD-L1 as well. On the basis of PD-L1 expression and EGFR mutation status, it may benefit NSCLC patients from individualized treatment. Meanwhile, patients who were under the age of 65, adenocarcinoma, well-differentiated and moderately-differentiated, hypo expression of PD-L1 have a relatively good prognosis, to provide reference for the prognosis evaluation of NSCLC.
【中文题目：非小细胞肺癌PD-1/PD-L1的表达与 EGFR突变相关性研究】 【中文摘要：背景与目的 肺癌的治疗模式以表皮生长因子受体酪氨酸激酶抑制剂（epidermal growth factor receptor-tyrosine kinase inhibitors, EGFR-TKIs）作为EGFR突变的非小细胞肺癌（non-small cell lung cancer, NSCLC）患者一线治疗；同时以程序性死亡受体1（programmed death receptor 1, PD-1）及其配体（programmed death receptor ligand 1, PD-L1）抑制剂为代表的免疫检查点抑制剂（immune checkpoint inhibitors, ICIs）的免疫治疗在肺癌治疗中疗效显著。本研究旨在探讨PD-1和PD-L1在NSCLC中的表达及其与临床病理特征、EGFR突变之间的关系。方法 采用免疫组化方法检测127例NSCLC PD-1和PD-L1蛋白表达，同时用定量聚合酶链反应（quantitative polymerase chain reaction, qPCR）检测EGFR基因突变，分析其与临床病理特征之间的关系，研究PD-1、PD-L1表达之间以及其与EGFR突变的关系。结果 NSCLC肿瘤细胞及肿瘤浸润免疫细胞PD-1阳性表达53.5%（68/127），肿瘤细胞PD-L1表达57.5%（73/127），PD-1和PD-L1的表达在低分化癌、临床分期I期+II期明显高于高中分化癌、III期+IV期（均P<0.05）；EGFR突变率为46.5%（59/127），EGFR突变的患者中女性、无吸烟史、腺癌、高中分化组分别高于男性、吸烟史、鳞癌、低分化组患者（均P<0.05）；NSCLC患者PD-L1与PD-1蛋白表达存在一致性（kappa=0.107,5, P=0.487），EGFR突变与PD-1、PD-L1表达存在负相关关系（Φ=-0.209，Φ=-0.221，均P<0.05）；对NSCLC患者随访，在<65岁、腺癌、高中分化癌、PD-L1表达的患者中位总生存期分别高于≥65岁、鳞癌、低分化癌、PD-L1不表达患者（均P<0.05）。PD-L1低表达患者中位生存期明显高于高表达患者（P=0.04）。结论 参照《非小细胞肺癌PD-L1免疫组织化学检测规范中国专家共识》检测非小细胞肺癌PD-L1表达，筛选出抗PD-1/PD-L1治疗的优势人群；同时检测出EGFR突变的患者，并且EGFR突变与PD-1、PD-L1表达存在负相关关系，依据PD-L1表达和EGFR突变状态，可能使NSCLC患者在的个体化治疗中获益，同时65岁以下、腺癌、高中分化、PD-L1低表达的患者有相对好的预后，为NSCLC预后评估提供参考。 】 【中文关键词：肺肿瘤；程序性死亡受体1；程序性死亡配体1；EGFR基因；免疫组化】.
Keywords: Epidermal growth factor receptor; Immunohistochemical; Lung neoplasms; Programmed death receptor 1; Programmed death receptor ligand 1.