IMMUNOREACT 9 metachronous rectal cancers have high HLA-ABC expression on healthy epithelium but a lower infiltration of CD3+ T cells than primary lesions.

ABSTRACT: Lynch syndrome is rarely associated with rectal cancer (RC) and thus, metachronous RC has been scarcely investigated. This study aimed to analyze the mucosal immune microenvironment in sporadic and metachronous RC. We analyzed the mucosal immune microenvironment in the 25 metachronous RCs present in the IMMUNOREACT 1 and 2 multicentre observational studies (624 patients). A panel of immune markers was retrospectively investigated at immunohistochemistry: CD3, CD4, CD8, CD8b, Tbet, FoxP3, PD-L1, MSH6, and PMS2 and CD80. Single-cell suspensions were subjected to flow-cytometry to determine the proportion of epithelial cells (pan-cytokeratin) acting as antigen-presenting cells (expressing CD80, CD86, HLA-ABC) and the proportion of activated CD8 + T cells (CD8 + positive for CD28, CD38), inhib

SUBMITTER: Salmaso B 

PROVIDER: S-EPMC11608249 | biostudies-literature | 2024 Nov

REPOSITORIES: biostudies-literature