The expression status and clinical value of TIM-3 in intrahepatic cholangiocarcinoma

BACKGROUND: T cell immunoglobulin and mucin-domain containing protein 3 (TIM-3) is an immune checkpoint that plays a crucial role in immune exhaustion. High expression of TIM-3 has been implicated in exerting immunosuppression across a variety of malignant tumors. Elucidating the expression profile of TIM-3 and its prognostic impact may hold great significance for the therapeutic management of intrahepatic cholangiocarcinoma (ICC). METHODS: We analyzed 117 ICC patients using immunohistochemical staining for TIM-3 and other immune checkpoints to examined their expression and immune cell infiltration in ICC tissue samples. Furthermore, the correlation of checkpoint expression with clinical characteristics and prognosis were analyzed. RESULTS: High expression of TIM-3 in tumor cells was observed in 61 patients (52.1%) and was significantly correlated with poorer tumor differentiation (P = 0.019). Survival analysis showed that high TIM-3 expression in tumor cells was a prognostic factor for disease-free survival (DFS) and overall survival (OS) in univariate analysis, and an independent risk predictor for DFS in multivariate analysis (P = 0.048, HR = 1.589, 95%CI = 1.004-2.515). Furthermore, TIM-3 expression in ICC tissues was significantly correlated with CD4⁺ and CD8⁺ tumor-infiltrating lymphocytes (both P < 0.005). CONCLUSION: Patients with high TIM-3 expression in tumor cells had shorter DFS and OS, which could serve as a valuable biomarker for predicting the inflammatory status and prognosis of ICC. Targeting TIM-3 may represent a promising therapeutic strategy for ICC.