Predictive value analysis of CEA, CA125 and CYFRA21-1 levels in evaluating the efficacy of tislelizumab combined with gemcitabine-cisplatin chemotherapy in patients with advanced non-small cell lung cancer.

While chemoimmunotherapy is the standard for advanced non-small cell lung cancer (NSCLC), effective and accessible tools for monitoring early treatment response are needed. The present study evaluated the clinical efficacy and safety of tislelizumab + gemcitabine-cisplatin (GP) chemotherapy vs. GP alone in NSCLC, and assessed serum CEA, CA125 and cytokeratin 19 fragment (CYFRA21-1) levels for treatment monitoring. In total, 90 patients with advanced NSCLC (from January 2021 to December 2024) were randomized in a 1:1 manner to receive tislelizumab + GP (n=45) or GP chemotherapy alone (n=45). Outcomes included short-term response [objective response rate (ORR) and disease control rate (DCR)], long-term progression-free survival (PFS) and overall survival (OS) (data cut-off, May 31, 2025; median follow-up, 23.5 months), 3-month biomarker changes and adverse events (AEs). The tislelizumab + GP group demonstrated numerically higher ORR/DCR (P>0.05), significantly longer median PFS (20.8 vs. 10.0 months, P=0.03) and a trend toward improved OS (not reached vs. 16.0 months; P=0.095). Post-treatment biomarker levels were significantly decreased in the study group (P<0.05) with comparable AEs. Receiver operating characteristic curves analyzed the diagnostic value of the combined biomarker panel compared with each biomarker individually for the prediction of short-term efficacy, which demonstrated significantly enhanced performance for the combination (P<0.05). In conclusion, combined CEA, CA125 and CYFRA21-1 effectively evaluated short-term efficacy. Furthermore, tislelizumab + GP demonstrated favorable safety and improved survival outcomes (particularly PFS) within follow-up.