Distribution and Prognostic Significance of T Cell Phenotypes in the Immune Microenvironment of Esophageal Adenocarcinoma and Barrett Esophagus

The T cell composition of the tumor microenvironment (TME) of esophageal adenocarcinoma (EAC) in comparison to the T cell composition of the TME of Barrett esophagus (BE) and in the context of clinicopathologic features and patient survival is unknown. To help fill these knowledge gaps, we used a multiplex immunofluorescence platform to study adaptive T cells and T cell subtypes based on costimulatory/inhibitory markers in EAC (n=54) and matched BE (n=21) samples from 54 patients with EAC and correlated the T cell phenotype distribution with clinicopathologic features and disease-free survival. We observed significant enrichment of cytotoxic T cells (CTCs), memory T cells, effector memory T cells, memory T regulatory cells (MTregs), and T cells expressing costimulatory/inhibitory markers LAG3, TIM3, and ICOS in EAC compared to BE, in the stroma. In EAC, increased TIM3 expression on T cells significantly correlated with increased CTCs but not T regulatory cells (Tregs). In EAC, higher densities of Tregs and MTregs correlated with pT1 disease, low pathologic stage, and absence of lymphovascular invasion. In EAC, patients with higher density of TIM3-expressing T cells had shorter disease-free survival by univariate and multivariate analyses. Our results identify T cell subtypes that are relevant to EAC biology and patient outcome. Furthermore, our results identify TIM3 as a potential target for optimization of immunomodulatory therapy in EAC.