Analysis of immune landscape in pancreatic and ileal neuroendocrine tumors demonstrates an immune cold tumor microenvironment

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Introduction: Neuroendocrine tumors (NETs) are rare tumors with an increasing incidence. While low and intermediate-grade pancreatic (PNET) and ileal (INET) tumors are slow-growing, they have a relatively high rate of metastasis to the liver where the outcome is much worse. For most cancers, the outcome is determined by the quality of the anti-tumor immune response. However, the quality and significance of anti-tumor responses in NETs are incompletely understood.

Aim(s): This study provides clinico-pathological analyses of the tumor immune microenvironment in PNET and INETs.

Materials and methods: Formalin-fixed paraffin-embedded tissue from consecutive resected PNETs (61) and INETs (131) were used to construct tissue microarrays (TMA); 1mm cores were taken from the tumor centre, stroma, tumor edge and adjacent healthy tissue. TMAs were stained with antibodies against CD8, CD4, CD68, FoxP3, CD20 and NCR1. T cell counts were compared with counts from non-small cell lung cancers (NSCLCs).

Conference: 18th Annual ENETS Concerence (2021)

Presenting Author:

Authors: Tanno L, Naheed S, Dunbar J, Tod J, Lopez M,

Keywords: pancreatic neuroendocrine tumor, ileal neuroendocrine tumor, tumor immune microenvironment, tumor infiltrating lymphocytes,