The Relationship Between the Tertiary Lymphoid Structure and Immune-infiltrating Cells in Gastrointestinal Cancers: A Systematic Review and Meta-analysis

Objectives: This study systematically evaluated the relationship between tertiary lymphoid structures (TLS) and clinical pathological features as well as immune infiltrating cells in gastrointestinal cancers.

Methods: We searched Web of science, Pubmed, Embase, and Cochrane Library for studies that met the requirements as of July 1, 2023, and the odds ratio, the corresponding 95% confidence interval or mean and standard deviation, were included in the analysis.

Findings: We eventually included 20 studies, involving a total of 4856 patients. TLS were found to be significantly associated with T stage, N stage, TNM stage, and tumor size. Moreover, patients with positive TLS showed significantly elevated expression of T-cell related markers, including CD3, CD4, CD8, CD45RO; B-cell related markers, such as CD11c and CD20; and dendritic cell-related marker CD103. On the other hand, positive TLS correlated significantly with low expression of FOXP3 and CD68. Additionally, there was a significant positive association between TLS and overall infiltration of tumor-infiltrating lymphocytes.

Conclusion: The presence of TLS is significantly correlated with the infiltration of various immune cells in gastrointestinal cancers. To determine the ideal balance between the presence of mature TLS and appropriate immune cell infiltration, further high-quality and multicenter clinical studies need to be conducted.