Abstract 1527: Exploring the role of tertiary lymphoid structure in the tumor microenvironment of cholangiocarcinoma

Abstract Cholangiocarcinoma is the second most common hepatobiliary malignant tumor besides liver cancer, grows from bile duct epithelial cells. However, surgery is the only hope for most patients with cholangiocarcinoma, but the effectiveness of treatment is not outstanding. Even though other methods of treatment, such as chemotherapy and radiation therapy, have limited effects. The immunotherapy and precision treatment have become the latest expectations of patients. Here, we analyzed the TCGA and GEO database to classify the cold and hot tumor using hierarchical clustering. The MCP counter results demonstrated that two genes, MS4A1 and CD79A, could identify the hot and cold tumor subgroups after TCGA data training and similar results show in GEO database. We also performed the tissue array for 105 cholangiocarcinoma tissue samples and found patients with high expression levels of MS4A1 or CD79A have better disease free survival (DFS) and progression free survival (PFS) (p value =0.0131 and 0.0017). In addition, we tested the tertiary lymphoid structures (TLS) signatures in tissue array sections, which is associated with the present of MS4A1 and CD79A. The results shows that patients who received the immunotherapy with TLS signatures have longer overall survival (OS) and PFS (p value =0.017 and 0.006). Collectively, B cell lineages or TLS could be an ideal biomarker to lead the clinical treatment and wish can broader applications in other diseases. Citation Format: Shin-Yi Chung, Ming-Huang Chen, Yi-Chen Yeh, Yu-Chan Chang, Yu-Cha Wang. Exploring the role of tertiary lymphoid structure in the tumor microenvironment of cholangiocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1527.