Division of Thoracic Oncology, Shizuoka Cancer Center, 1007 Shimonagakubo, Nagaizumi-cho, Suntou-gun, Shizuoka, Shizuoka, 411-8777, Japan.
Division of Pathology, Shizuoka Cancer Center, Shizuoka, Japan.
Int J Clin Oncol. 2018 Dec;23(6):1052-1059. doi: 10.1007/s10147-018-1305-4. Epub 2018 Jun 15.
The expression of programmed death ligand 1 (PD-L1) is considered a predictive biomarker of anti-programmed death 1 (PD-1)/PD-L1 cancer therapies. However, changes in PD-L1 expression of tumor cells during clinical courses have not been fully evaluated. We evaluated changes in PD-L1 expression for non-small cell lung cancer (NSCLC) patients who received anticancer treatments during clinical courses.
In 76 NSCLC patients, PD-L1 expression was evaluated before and after anticancer treatment by immunohistochemical (IHC) analysis using an anti-PD-L1 antibody. We defined two cut-off points of PD-L1 expression (1 and 50%) and three corresponding IHC groups (A: 0%, B: 1-49%, and C: ≥50%). IHC group B and C were considered to be positive expression, and we defined the difference of IHC group between pre- and post-treatment as 'major change' in PD-L1 expression.
Before anticancer treatment, PD-L1 expression was observed in 38/76 (50%) patients, and was significantly less common in patients harboring mutations in the epidermal growth factor receptor gene (EGFR) than in those without (P = 0.039). After anticancer treatment, PD-L1 expression was observed in 36/76 (47%) patients. Major increases in PD-L1 expression were seen in 11 (14%), and major decreases in 18 (24%) patients. Among 13 patients harboring EGFR mutations treated with EGFR tyrosine-kinase inhibitor (EGFR-TKI), five (38%) showed major increases.
Major changes of PD-L1 expression in tumor cells were observed in 38% of NSCLC patients who received anticancer treatments. And, treatments with EGFR-TKI may increase PD-L1 expression in NSCLC patients harboring EGFR mutations.
程序性死亡配体 1（PD-L1）的表达被认为是抗程序性死亡 1（PD-1）/PD-L1 癌症治疗的预测生物标志物。然而，肿瘤细胞 PD-L1 表达在临床过程中的变化尚未得到充分评估。我们评估了在临床过程中接受抗癌治疗的非小细胞肺癌（NSCLC）患者的 PD-L1 表达变化。
在 76 例 NSCLC 患者中，通过使用抗 PD-L1 抗体的免疫组织化学（IHC）分析评估了抗癌治疗前后的 PD-L1 表达。我们定义了 PD-L1 表达的两个截止点（1 和 50%）和三个相应的 IHC 组（A：0%，B：1-49%，和 C：≥50%）。IHC 组 B 和 C 被认为是阳性表达，我们将治疗前后 IHC 组的差异定义为 PD-L1 表达的“主要变化”。
在抗癌治疗前，38/76（50%）例患者观察到 PD-L1 表达，携带表皮生长因子受体基因（EGFR）突变的患者比无突变的患者明显较少（P=0.039）。在抗癌治疗后，36/76（47%）例患者观察到 PD-L1 表达。11 例（14%）患者的 PD-L1 表达显著增加，18 例（24%）患者的 PD-L1 表达显著减少。在 13 例接受 EGFR 酪氨酸激酶抑制剂（EGFR-TKI）治疗的 EGFR 突变患者中，有 5 例（38%）表现出主要增加。
在接受抗癌治疗的 NSCLC 患者中，38%的患者观察到肿瘤细胞 PD-L1 表达的主要变化。并且，EGFR-TKI 治疗可能会增加携带 EGFR 突变的 NSCLC 患者的 PD-L1 表达。
