CD103-Positive Tumor-Infiltrating Lymphocytes Predict a Favorable Prognosis in Colorectal Cancer with Liver...

Area of Science:

• Immunology
• Oncology
• Surgical Pathology

Background:

• CD103+ tumor infiltrating lymphocytes (TILs) are linked to better survival in colorectal cancer.
• The role of CD103+ TILs in colorectal liver metastasis (CRLM) spatial distribution and prognosis is not well understood.

Purpose of the Study:

• To investigate the spatial distribution and prognostic significance of CD103+ TILs in primary colorectal tumors (PT) and colorectal liver metastasis (LM).
• To characterize CD103+ TIL subsets and their functional differences in PT versus LM.

Main Methods:

• Analysis of 84 CRLM patients undergoing simultaneous resection of PT and LM.
• Immunohistochemistry and multiplex immunofluorescence to quantify CD103+ TILs abundance and subsets.
• Single-cell RNA sequencing and spatial transcriptomics to assess functional characteristics of CD103+CD8+ T cells.

Main Results:

• CD103+ TIL infiltration in PT did not correlate with CRLM patient prognosis.
• Increased CD103+ TILs in LM, particularly in stromal compartments of the tumor center, were associated with improved survival.
• CD103+ TILs in LM were predominantly CD8+CD103+ and CD4+CD103+ cells, with CD8+CD103+ T cells in LM exhibiting tissue-resident memory features.

Conclusions:

• Spatial distribution of CD103+ TILs differs significantly between PT and LM.
• CD103+ TIL infiltration in LM is a significant independent prognostic biomarker for CRLM patients.