TIGIT Expression and Its Implications in Non-Small-Cell Lung Cancer Progression and Therapy: A Systematic Review

Lung cancer (LC) is the leading cause of cancer-related mortality worldwide, with non-small-cell lung cancer (NSCLC) representing 85-90% of cases. Despite the efficacy of PD-1/PD-L1 immune checkpoint inhibitors, primary and acquired resistance highlight the need for novel immunotherapeutic strategies. A systematic review of the literature from 2020 to 2025 was conducted according to the PICO model. Six studies were included, encompassing phase I-III clinical trials. The analysis focused on efficacy, safety, and emerging therapeutic strategies targeting TIGIT in NSCLC. TIGIT blockade enhances cytotoxic T lymphocyte and natural killer (NK) cell activity, strengthening antitumor immunity. Clinical trials, particularly with the monoclonal antibody tiragolumab combined with PD-1/PD-L1 inhibitors, show promising synergistic effects. Emerging strategies, including bispecific antibodies (e.g., TIGIT/PD-1 and TIGIT/PD-L1) and experimental cell therapies, are under investigation to further improve the antitumor response. Anti-TIGIT therapies represent a highly promising approach in NSCLC. While phase III data remain limited, biomarker-driven, well-designed trials are essential. If validated, TIGIT blockade could become a key addition to immuno-oncology treatment strategies for NSCLC.