Changes in soluble PD-L1 levels in patients with advanced non-small cell lung cancer

Soluble programmed death-1 ligand (sPD-L1) in the serum of non-small cell lung cancer (NSCLC) patients is a crucial factor in disease prognosis and an indicator for immunotherapy response. This study aimed to evaluate changes in sPD-L1 levels in advanced NSCLC patients. Between May 2018 and October 2022, 80 patients with advanced-stage NSCLC and 30 healthy volunteers participated in a prospective study.

The findings revealed a significant rise in sPD-L1 concentration in the lung cancer group compared to the normal control group (1.08 vs. 0.42, p < 0.001). No apparent correlation was found between sPD-L1 concentration and membrane-bound programmed death-1 ligand (mPD-L1) expression. The optimal diagnostic threshold for sPD-L1 was set at 0.92 ng/mL, showing a sensitivity of 56.25% and specificity of 77.33%, with an area under the curve (AUC) of 0.743 (p = 0.001).

Although increased sPD-L1 levels were prevalent in individuals with advanced age, prolonged disease duration, large tumor size, and finger clubbing, these associations did not reach statistical significance (p > 0.05). In conclusion, sPD-L1 levels significantly increased in advanced NSCLC patients compared to controls (p < 0.05), with no association observed with mPD-L1 (p = 0.304). The study suggests that sPD-L1 concentration can be a specific biomarker for guiding the diagnosis of advanced NSCLC, with a recommended cutoff value of 0.92 ng/mL, demonstrating a sensitivity of 56.25% and specificity of 77.33% (p = 0.001). Importantly, no apparent relationship was established between sPD-L1 levels and clinical or paraclinical characteristics in advanced NSCLC patients.