Immune checkpoints in tumor-infiltrating t lymphocytes in laryngeal cancer: Determination of expression levels of lymphocyte activation gene-3 (LAG-3), T cell immunoglobulin and mucin domain-containing protein-3 (TIM-3), and v-domain IG suppressor of T cell activation (VISTA)

Objective: In immunotherapy, the most prominent target molecules are Programmed Death-1 (PD-1) and Cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4). However, Lymphocyte Activation Gene-3 (LAG-3), T cell immunoglobulin and mucin domain-containing protein-3 (TIM-3), and V-domain Ig Suppressor of T cell Activation (VISTA) are alternative immune checkpoint molecules currently being investigated. The aim of this study is to evaluate the expression levels of LAG-3, TIM-3, and VISTA immune checkpoints in tumor-infiltrating T lymphocytes in laryngeal cancer cases and to investigate the impact of these immune checkpoints on disease prognosis and tumor characteristics. Material and Methods: This study included 132 patients who underwent surgery for advanced-stage laryngeal cancer with histopathological confirmation of squamous cell carcinoma between January 2010 and December 2020. Sociodemographic data, survival rates, disease-free survival information, and tumor pathological characteristics were obtained from hospital records and patient files. Immunohistochemical staining for LAG-3, TIM-3, VISTA, and CD8 was performed on pathology specimen blocks prepared from all cases. Results: The mean follow-up period for 132 patients with laryngeal carcinoma was 44.67 months (±33.51, min: 1, max: 126 months). At the end of the study, the overall survival (OS) rate for all laryngeal cancer cases was 69.7%, and the disease-free survival (DFS) rate was 78.8%. Five-year OS and DFS rates were 75.1% and 78.5%, respectively. LAG-3 overexpression was observed in 26.5% of cases, TIM-3 in 51.5%, and VISTA in 53%. The presence of LAG-3, TIM-3, and VISTA overexpression was not statistically associated with OS or DFS. However, in patients with LAG-3 overexpression, better outcomes in terms of recurrence and survival were observed, albeit without statistical significance. LAG-3-negative patients were significantly more likely to exhibit thyroid cartilage invasion compared to LAG-3-positive patients. Conclusion: This study found no significant impact of the investigated immune checkpoints on prognosis in advanced-stage laryngeal cancer cases. However, LAG-3, TIM-3, and VISTA were found to be highly overexpressed in tumor-infiltrating lymphocytes. Future studies should focus on exploring the therapeutic contributions of targeting these molecules individually or in combination, rather than their prognostic implications.