Prognostic significance of CD8 and TCF1 double positive T cell subset in microsatellite unstable gastric cancer

Abstract

Abstract Microsatellite instability-high (MSI-H) gastric cancer (GC) exhibits high tumor-infiltrating lymphocyte (TIL) density. Despite the recognized significance of the immune microenvironment in MSI-H GC, our understanding of TIL remains limited. This study aimed to investigate the clinicopathologic and prognostic implications of T cell subsets in MSI-H GC. Single immunohistochemistry (IHC) for CD8, TCF1, and CD103, and double IHC for CD8/TCF1 and CD8/CD103 were performed in 382 surgically resected MSI-H GC samples. Densities of single or double positive immune cells were quantified and correlated with clinicopathologic features and overall survival (OS). TCF1 + cell densities showed weak correlations with CD8 + and CD103 + cell densities, while CD8+/TCF1 + cell density moderately correlated with CD8+/CD103 + cell density (R2 = 0.539, p 0.05). Notably, elevated CD8+/TCF1 + cell density and a high CD8+/TCF1 + to CD8 + ratio correlated with less aggressive clinicopathologic features and improved OS (p = 0.017 and 0.001, respectively). Multivariable Cox-regression identified CD8+/TCF1 + to CD8 + ratio as an independent prognostic factor (p = 0.028). We demonstrated the prognostic significance of CD8+/TCF1 + to CD8 + ratio using double IHC in a large cohort of MSI-H GC.

Keywords

• Stomach neoplasms
• Microsatellite instability
• Tumor-Infiltrating Lymphocytes
• T cell transcription factor 1
• Alpha E integrins