Abstract NSCLC, as a major subtype of lung cancer, has a very poor prognosis for advanced patients, and although the application of immune checkpoint inhibitors has revolutionized the treatment paradigm, significant efficacy heterogeneity still exists. This study aimed to investigate the expression characteristics of TILs and PD-L1 in NSCLC and their prognostic value. By retrospectively analyzing the clinicopathological data of 50 surgically resected NSCLC patients from 2018–2023, IHC was used to detect the expression levels of CD4 + TILs, CD8 + TILs, CD68 + TAMs, and PD-L1 in the tumor tissues.The high expression rate of PD-L1 reached 70% (35/50), and the intensity of its expression was significantly correlated with the size of the tumor (p = 0.021); the percentage of high infiltration of CD8 + TILs reached 80% (40/50), which was positively correlated with lymph node metastasis (p = 0.004). Correlation analysis revealed that PD-L1 was positively correlated with CD8 + TILs infiltration (r = 0.327, p = 0.020) and negatively correlated with CD68 + TAMs (r=-0.369, p = 0.008). Survival analysis showed significantly longer median PFS in the CD4 + TILs low infiltration group (15 months vs. 6 months, p = 0.027), while OS was worse in the PD-L1 high expression group (HR = 2.850, p = 0.039). Multifactorial Cox regression confirmed PD-L1 high expression (HR = 3.093, p = 0.022) and lung adenocarcinoma pathologic type (HR = 2.898, p = 0.026) as independent risk factors for PFS. In NSCLC, high membrane-specific expression of PD-L1 was positively correlated with tumor load and was tissue-selective (tumor tissue vs. normal lung tissue); membrane-localized infiltration of CD8 + TILs was positively correlated with lymph node metastasis. high expression of PD-L1 and pathologic type (adenocarcinoma vs. squamous carcinoma) were independent risk factors for postoperative PFS; PD-L1 could be used as a positive predictive marker for OS. The combined PD-L1 expression and CD8 + TILs/CD68 + TAMs immune infiltration characteristics provide a theoretical basis for individualized immunotherapy.
Wang et al. (Tue,) studied this question.