Tertiary Lymphoid Structures in Colorectal Cancers and Their Prognostic Value

Abstract Introduction: Tumor-infiltrating lymphocytes (TIL) in tumor stroma are considered to be involved in elimination of malignant cells and in prevention of metastasis formation. TIL are consisted of T lymphocytes including cytotoxic lymphocytes that are a constituent part of the effector mechanism of anti-tumor immunity and B lymphocytes that can form tertiary lymphoid structures (TLS). TLS have been described in several solid tumors and in colorectal carcinoma (CRC) and they influence on the local and systemic anti-cancer response. The aim of this study was to quantify the presence of TLS in CRC patients and to determine their role in tumor progression. Patients and methods: The study included 103 patients with CRC who underwent surgery at the University Clinic of Digestive Surgery in Skopje, whose operative material was analyzed at the Institute of Pathology, Medical Faculty in Skopje. The density of TLS was determined and correlated with neoplasm status of local growth (T), positive lymph nodes, lymphatic invasion, stage of the disease and tumor grade. Results: The density of TLS was significantly higher in patients with higher stage, lower T status, negative lymph nodes, in patients with no lymphatic invasion and with better differentiated tumors. Conclusion: The density of TLS plays an important role in controlling the tumor growth and it can be a parameter for neoplasm progression in CRC patients. The density of TLS has influence on the control of tumor progression