Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Lung Cancer. 2018 Feb;116:1-6. doi: 10.1016/j.lungcan.2017.12.003. Epub 2017 Dec 7.
It was reported that programmed cell death-ligand 1 (PD-L1) expression is associated with smoking and wild-type epidermal growth factor receptor (EGFR) in lung adenocarcinoma. However, the association between PD-L1 expression and EGFR mutation site in EGFR mutation-positive lung adenocarcinoma is unclear.
We retrospectively examined the relationship between PD-L1 expression and EGFR status in 441 surgically resected primary lung adenocarcinomas. Membrane PD-L1 expression on tumor cells was evaluated by immunohistochemical analysis using a PD-L1 antibody (clone SP142) and defined by tumor proportion scores (TPSs) of 0%, 1-4%, 5-49%, and ≥50%, respectively.
Two hundred and eighteen (49.4%) patients had wild-type EGFR, and 223 (50.6%) had mutant EGFR-98 (44.0%) with exon 19 deletion, 116 (52.0%) with exon 21 L858R point mutation, and nine (4.0%) with another EGFR mutation. Overall, Fisher's exact test showed that PD-L1 positivity was associated with wild-type EGFR, and there was only one case with PD-L1 TPS ≥50% among the cases with mutant EGFR. The analysis of cases with mutant EGFR indicated no significant association between EGFR mutation site and PD-L1 expression. However, the prevalence of PD-L1 TPS 5-49% was higher among patients with EGFR exon 19 deletion than with EGFR exon 21 L858R point mutation.
PD-L1 expression was significantly associated with wild-type EGFR, and PD-L1 TPS ≥50% seldom overlaps with presence of driver oncogene EGFR. There was no significant difference in PD-L1 expression among the EGFR mutation sites.
有报道称程序性死亡配体 1（PD-L1）的表达与肺腺癌中的吸烟和野生型表皮生长因子受体（EGFR）有关。然而，PD-L1 表达与 EGFR 突变阳性肺腺癌中 EGFR 突变部位之间的关系尚不清楚。
我们回顾性分析了 441 例手术切除的原发性肺腺癌中 PD-L1 表达与 EGFR 状态之间的关系。使用 PD-L1 抗体（克隆 SP142）通过免疫组织化学分析评估肿瘤细胞上的膜 PD-L1 表达，并分别定义为肿瘤比例评分（TPS）为 0%、1-4%、5-49%和≥50%。
218 例（49.4%）患者 EGFR 为野生型，223 例（50.6%）患者 EGFR 为突变型，其中 19 号外显子缺失 44.0%，21 号外显子 L858R 点突变 52.0%，另一种 EGFR 突变 9.0%。总体而言，Fisher 确切检验显示 PD-L1 阳性与野生型 EGFR 相关，而在突变型 EGFR 病例中仅发现一例 PD-L1 TPS≥50%。对突变型 EGFR 病例的分析表明，EGFR 突变部位与 PD-L1 表达之间无显著相关性。然而，与 EGFR 外显子 21 L858R 点突变相比，EGFR 外显子 19 缺失患者中 PD-L1 TPS 为 5-49%的比例更高。
PD-L1 表达与野生型 EGFR 显著相关，PD-L1 TPS≥50%与驱动癌基因 EGFR 很少重叠。EGFR 突变部位之间 PD-L1 表达无显著差异。
