Abstract
BACKGROUND: Patients with programmed cell death-ligand 1 (PD-L1) ≥50% metastatic non-small cell lung cancer (NSCLC) treated with first-line immunotherapy showed heterogeneous tumor responses. In this study, we investigated the clinical and immune-inflammatory markers distinguishing patients with metastatic NSCLC achieving high depth of tumor response (HDPR) from those with non-high depth of response (NHDPR). The impact of clinical features on the prognosis of patients with PD-L1 ≥50% were further clarified. METHODS: The clinical characteristics and immune-inflammatory markers of 17 patients with PD-L1 ≥50% metastatic NSCLC at Beijing Tiantan Hospital between July 2020 and December 2023 were retrospectively analyzed. RESULTS: Among the 17 patients, seven (41.2%) patients achieved HDPR (range: -50%, -72%) and 10 (58.8%) patients achieved NHDPR (range: -13%, -45%). Below normal CD4 + T lymphocytes/CD8 + T lymphocytes (CD4/CD8) ratio (p = 0.01) and oncogenes and/or tumor suppressor gene mutations (TP53/KRAS/EGFR) (p = 0.001) were found enriched for NHDPR compared with HDPR. With a median follow-up of 26.0 months (range: 17.2-34.8 months), the median progression-free survival (PFS) following first-line immunotherapy and overall survival (OS) were 9.0 months (95% CI: 5.0-13.0) and not reached (NR), respectively. The neutrophil-to-lymphocyte ratio (NLR) was identified as an independent prognostic factor on first-line PFS. Patients with an NLR ≥4 exhibited a shorter median PFS (7.0 months vs. NR; p = 0.033; 95% CI: 1.2-80.2) than those with an NLR <4 following first-line immunotherapy. CONCLUSIONS: Among patients with PD-L1 ≥50% metastatic NSCLC who received first-line immunotherapy, a lower CD4/CD8 ratio and the presence of genes mutations showed a diminished tumor response and a higher NLR ratio exhibited a worse median PFS.