表皮生长因子受体酪氨酸激酶抑制剂（EGFR-TKI）抵抗性，包括奥西替尼，与EGFR突变非小细胞肺癌（NSCLC）中程序性细胞死亡配体-1（PD-L1）表达状态之间的关系尚不清楚。我们对64例EGFR外显子19缺失（ex19del）或EGFR外显子21 L858R置换（L858R）携带者，接受奥西替尼作为一线治疗的晚期不能手术或转移性NSCLC患者进行了回顾性分析。我们使用Kaplan-Meier生存曲线和log-rank检验比较了PD-L1肿瘤比例分数（TPS）≥20%和PD-L1 TPS <20%的符合条件的患者之间的无进展生存期（PFS）。我们进行了多变量分析，以考察PFS的不良预后因素。PD-L1 TPS ≥20%组包括22例（中位数[范围]年龄：70.5 [33-86]岁；10名女性[45.5%]；11名吸烟者或戒烟者[50%]）；相应地，16/4/1/1例患者的ECOG状况为0-1/2/3/4。PD-L1 TPS <20%组包括42例患者（中位数[范围]年龄：73[43-88]岁；29名女性[69%]；28.6%的患者为吸烟者或戒烟者）；相应地，33/6/3/0例患者的ECOG状况为0-1/2/3/4。PD-L1 TPS ≥20%组和PD-L1 TPS <20%组的中位无进展生存期分别为9.1和28.1个月（log-rank p=0.013）。多变量分析显示PD-L1 TPS ≥20%与PFS相关（风险比: 2.35，95%置信区间: 1.09-5.08，p=0.030）。EGFR突变NSCLC患者中PD-L1 TPS ≥20%可能与对奥西替尼产生早期耐药性相关。©2023作者。由John Wiley & Sons Ltd出版的癌症医学。

The relationship between epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) resistance, including osimertinib, and programmed cell death-ligand 1 (PD-L1) expression status in EGFR-mutated non-small cell lung carcinoma (NSCLC) remains unclear.We retrospectively analyzed 64 patients with unresectable advanced or metastatic NSCLC carrying EGFR exon 19 deletions (ex19del) or EGFR exon 21 L858R substitutions (L858R) who received osimertinib as the first-line treatment. We compared progression-free survival (PFS) between eligible patients with PD-L1 tumor proportion scores (TPS) ≥20% and PD-L1 TPS <20% using the Kaplan-Meier survival plots with a log-rank test. Multivariate analysis was performed to examine the poor prognostic factors of PFS.The PD-L1 TPS ≥20% group included 22 cases (median [range] age: 70.5 [33-86] years; 10 women [45.5%]; 11 current or ex-smokers [50%]); ECOG performance status (PS) of 0-1/2/3/4 was noted in 16/4/1/1 patients, respectively. The PD-L1 TPS <20% group included 42 patients (median [range] age 73 [43-88] years; 29 women [69%]; 12 current or ex-smokers [28.6%]); ECOG PS of 0-1/2/3/4 was noted in 33/6/3/0 cases, respectively. The median PFS was 9.1 and 28.1 months in the PD-L1 TPS ≥20% and PD-L1 TPS <20% groups, respectively (log-rank p = 0.013). Multivariate analysis revealed that PD-L1 TPS ≥20% was associated with PFS (hazard ratio: 2.35, 95% confidence interval: 1.09-5.08, p = 0.030).PD-L1 TPS ≥20% in patients with EGFR-mutated NSCLC may be associated with early resistance to osimertinib.© 2023 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.