Dynamic combined monitoring of SII and PNI in evaluating the prognostic impact on advanced driver gene–negative NSCLC patients receiving immunotherapy.

Abstract

e20614 Background: In recent years, immune checkpoint inhibitors (ICIs) have become an important treatment option for patients with advanced, driver gene-negative non-small cell lung cancer (NSCLC). This study aims to explore the correlation and predictive value of peripheral blood indicators and clinical characteristics, both before and early during treatment with PD-1 (programmed cell death-1) monoclonal antibody therapy, in relation to the efficacy and prognosis of advanced NSCLC patients. Methods: A retrospective analysis was conducted on patients with advanced, driver gene-negative NSCLC treated with PD-1 inhibitors (either as monotherapy or in combination with chemotherapy) at Zhongda Hospital Southeast University between September 2021 and September 2024. Clinical and laboratory data, including LDH, SII, and PNI, were collected before and after two treatment cycles. Efficacy was assessed using RECIST 1.1, and optimal cutoff values were determined through ROC analysis. Kaplan-Meier and Cox regression analyses were used to identify independent prognostic factors. A prognostic model and nomogram were developed, and their performance was evaluated using C-index, calibration, and ROC AUC. Results: A total of 90 patients were included in the study. ROC analysis determined the optimal cutoff values for pre-treatment and post-treatment (after two cycles) LDH, SII, and PNI. Univariate analysis showed that LDH (T0) ≤ 235.2, LDH (T2) ≤ 227.5, SII (T2) ≤ 631.8, PNI (T2) > 42.6, and the absence of liver metastasis were associated with higher disease control rate (DCR) after four cycles (P < 0.05). LDH (T2) ≤ 227.5, SII (T2) ≤ 631.8, PNI (T2) > 42.6, and the absence of liver metastasis were linked to longer progression-free survival (PFS) (P < 0.05). Pre-treatment LDH ≤ 235.2, post-treatment LDH ≤ 227.5, SII ≤ 631.8, PNI > 42.6, and the absence of liver metastasis were associated with better overall survival (OS) (P < 0.05). Multivariate analysis identified LDH (T2), PNI (T2), and liver metastasis as independent predictors of DCR, PFS, and OS. The multivariate model showed that a greater number of favorable factors was associated with a better prognosis (P < 0.001). Based on these independent factors, nomograms for PFS and OS were developed using R software, with C-indices of 0.786 and 0.792, both > 0.75. Calibration and ROC curve validation indicated good predictive performance for both models. Conclusions: In advanced, driver gene-negative NSCLC patients undergoing ICI treatment, post-treatment (after two cycles) LDH, PNI, and the absence of liver metastasis were associated with treatment efficacy and identified as independent predictive factors. Additionally, post-treatment (after two cycles) SII, PNI, and LDH levels were correlated with patient prognosis and were also independent predictive factors.