Depleted polymorphonuclear leukocytes in human metastatic liver reflect an altered immune microenvironment associated with recurrent metastasis.

Background: Hepatic immunity, normally protective against neoplasia, is subverted in colorectal liver metastasis (CRLM). Here, we compare the inflammatory microenvironment of CRLM-bearing liver tissue to donor liver.

Methods: Twenty-five patients undergoing resection for CRLM were recruited, 13 of whom developed intrahepatic recurrence within 18 months.

Human Tumor-Infiltrating Myeloid Cells: Phenotypic and Functional Diversity.

Our current understanding of human tumor-resident myeloid cells is, for the most part, based on a large body of work in murine models or studies enumerating myeloid cells in patient tumor samples using immunohistochemistry (IHC). This has led to the establishment of the theory that, by and large, tumor-resident myeloid cells are either "protumor" M2 macrophages or myeloid-derived suppressor cells (MDSC). This concept has accelerated our understanding of myeloid cells in tumor progression and enabled the elucidation of many key regulatory mechanisms involved in cell recruitment, polarization, and activation.