NSCLC转移淋巴结PD-L1表达分析及对一线TKI或化疗结局的影响OA

[Objective]To investigate the heterogeneity of PD-L1 expression profiles between primary tumors and paired metastatic lymph nodes in advanced non-small cell lung cancer(NSCLC),and to determine the predictive value of key immune marker expression for the efficacy of first-line targeted therapy and chemotherapy.[Methods]A retrospective analysis was conducted on 128 patients with histologically confirmed NSCLC and corresponding metastatic lymph nodes,who received first-line tyrosine kinase inhibitors(TKIs)or platinum-based doublet chemotherapy at Guangdong Provincial People's Hospital between April 2017 and February 2020.Immunohistochemistry(IHC)was employed to evaluate PD-L1 expression in primary tumors and metastatic lymph nodes.The Wilcoxon signed-rank test was performed to compare PD-L1 expression characteristics between primary tumors and metastatic lymph nodes.Kaplan-Meier survival curves were constructed,and the Log-rank test was used to compare differences between groups.[Results]Among 28 paired cases,PD-L1 expression levels were numerically higher in metastatic lymph nodes than in primary NSCLC tumors(median:32.5 vs.10.0),although the difference did not reach statistical significance(MD=5.000,P=0.083).Survival analysis revealed that in patients with driver gene-positive NSCLC,high PD-L1 expression(TPS≥50%)in lymph nodes was significantly associated with shorter progression-free survival(PFS)following first-line TKI therapy[median PFS:4.0(TPS≥50%)vs.8.9(1%≤TPS＜50%)vs.18.0(TPS＜1%)months,χ2=15.284,P＜0.001].Conversely,in patients with driver gene-negative NSCLC,high PD-L1 expression in lymph nodes was associated with longer PFS[median PFS:7.9(TPS≥50%)vs.3.0(1%≤TPS＜50%)months,χ2=8.436,P=0.004]and overall survival(OS)[median OS:28.8(TPS≥50%)vs.14.2(1%≤TPS＜50%)months,χ2=4.010,P=0.045]after first-line chemotherapy.[Conclusion]PD-L1 expression in metastatic lymph nodes is largely consistent with that in primary tumors of patients with advanced NSCLC.High PD-L1 expression in lymph nodes is associated with improved survival outcomes in driver gene-negative patients undergoing chemotherapy,whereas it portends a poor prognosis with TKI treatment in driver gene-positive patients.These findings support the application of PD-L1 expression levels in metastatic lymph nodes to guide personalized precision medicine strategies for advanced NSCLC.