BACKGROUND PD-1/PD-L1 inhibitors is the important drugs of immunotherapy for malignant tumors. PD-L1 expression is an important biomarker of selecting patients for ICIs therapy. However, the correlation of PD-L1 expression with clinicopathologic features in lung adenocarcinoma remains controversial. METHODS PD-L1 expression was tested using clone SP263 by immunohistochemistry (IHC) on Ventana automated Benchmark in tissue micro-arrays (TMA) in lung adenocarcinoma. The association of PD-L1 expression with clinicopathologic characteristics, including gender, age, histological subtype, smoking history, stage, and genotype were analyzed. RESULTS 404 patients were available for analyzing. The incidence of PD-L1 expression was 22.5% (using a cutoff of ≥ 25%). Statistical analysis showed PD-L1 expression was associated with advanced stage, lymph node (LN) metastasis, solid predominant subtype and wild-type epidermal growth factor receptor (EGFR) gene. In subgroup analysis, PD-L1 expression in patients with EGFR exon 19 deletions was higher than that of with EGFR L858R mutation at exon 21 (21.6% vs. 10.2%, P = 0.046). In multivariate analysis for overall survival (OS) by Cox hazard proportion model, patients with EGFR gene mutations (HR 1.635, 95% CI 1.310-2.040, P < 0.001) and early stage (HR 2.495, 95% CI 2.003-3.106, P < 0.001) had a longer survival, while PD-L1 expression was not associated with overall survival (HR 0.847, 95% CI 0.655-1.094, P = 0.203). CONCLUSION For patients with lung adenocarcinoma, LN metastasis, wild-type EGFR, advanced stage, solid predominant subtype were independent predictors of PD-L1 expression by multivariate analysis. PD-L1 expression may be not a predictor of OS for patients with lung adenocarcinoma.

中文翻译：

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404例肺腺癌患者PD-L1表达与临床病理特征的相关性

背景技术PD-1 / PD-L1抑制剂是免疫治疗恶性肿瘤的重要药物。PD-L1表达是选择患者进行ICIs治疗的重要生物标志物。然而，PD-L1表达与肺腺癌临床病理特征的相关性仍存在争议。方法采用克隆SP263，通过免疫组织化学（IHC）在肺腺癌组织微阵列（TMA）中的Ventana自动Benchmark上测试PD-L1的表达。分析了PD-L1表达与临床病理特征，包括性别，年龄，组织学亚型，吸烟史，分期和基因型的关系。结果404例患者可供分析。PD-L1表达的发生率为22.5％（使用≥25％的临界值）。统计分析表明PD-L1表达与晚期有关，淋巴结（LN）转移，固体优势亚型和野生型表皮生长因子受体（EGFR）基因。在亚组分析中，EGFR外显子19缺失患者的PD-L1表达高于外显子21处EGFR L858R突变患者的PD-L1表达（21.6％vs. 10.2％，P = 0.046）。在通过Cox风险比例模型进行的总生存（OS）的多变量分析中，EGFR基因突变（HR 1.635，95％CI 1.310-2.040，P <0.001）和早期（HR 2.495，95％CI 2.003-3.106，P）的患者<0.001）的生存期更长，而PD-L1的表达与总体生存率无关（HR 0.847，95％CI 0.655-1.094，P = 0.203）。结论对于肺腺癌患者，LN转移，野生型EGFR，晚期，实体优势亚型是PD-L1表达的独立预测因素。