To investigate the predictive value of dynamic monitoring of circulating tumor DNA (cfDNA), neutrophil-to-lymphocyte ratio (NLR), and programmed cell death ligand 1 messenger RNA (PD-L1 mRNA) for immunotherapy efficacy and prognosis in patients with non-small cell lung cancer (NSCLC).

A total of 42 patients with advanced NSCLC admitted to our hospital from January 2019 to June 2022 were selected and divided into an observation group 22 cases and a control group 20 cases based on immunotherapy efficacy. cfDNA concentration, NLR, and PD-L1 mRNA expression levels were measured before and after treatment, and the rate of change for each indicator was calculated. Receiver operating characteristic (ROC) curves were used to analyze the predictive value of single indicators and the combined model for objective response rate (ORR). Cox proportional hazards regression was used to analyze the association between dynamic changes in the indicators and progression-free survival (PFS).

After treatment, cfDNA, NLR, and PD-L1 mRNA levels in the observation group were lower than those in the control group, and the absolute values of the rate of change were greater than those in the control group (P<0.05). Compared with the control group, the observation group showed: cfDNA rate of change [(-24.46±8.11)% vs. (-16.40±8.93)%, t=3.064, P=0.004]; NLR rate of change [(-24.51±6.86)% vs. (-15.75±10.65)%, t=3.196, P=0.003]; PD-L1 mRNA rate of change [(-20.29±5.89)% vs. (-15.83±5.10)%, t=2.607, P=0.013]. ROC curve analysis showed that the area under the curve (AUC) for predicting ORR was 0.761 (95%CI: 0.605~0.879) for cfDNA rate of change, 0.748 (95%CI: 0.590~0.869) for NLR rate of change, and 0.732 (95%CI: 0.573~0.857) for PD-L1 mRNA rate of change. The combined model of the three indicators yielded an AUC of 0.895 (95%CI: 0.762~0.968), with a sensitivity of 90.91% and a specificity of 80.00%, which was superior to any single indicator. Multivariate Cox regression analysis showed that cfDNA rate of change ≤20% (HR=6.541, 95%CI: 1.336~31.333, P=0.019), NLR rate of change ≤22% (HR=7.910, 95%CI: 1.538~40.684, P=0.013), and PD-L1 mRNA rate of change ≤20% (HR=6.501, 95%CI: 1.038~40.705, P=0.045) were risk factors for shortened PFS in NSCLC patients receiving immunotherapy.

Dynamic monitoring of cfDNA, NLR, and PD-L1 mRNA can effectively predict immunotherapy efficacy and prognosis in NSCLC patients. The combination of these three indicators provides a reference for clinical individualized treatment decisions.