Programmed Cell Death Ligand 1 Expression in CD163+ Tumor-associated Macrophages in Cancer Gland Rupture Microenvironment

Abstract

In this study, we aimed to examine the relationship among cancer gland rupture microenvironment, programmed cell death ligand 1 (PD-L1) expression in CD163+ tumor-associated macrophages (TAMs), and prognosis in colon adenocarcinoma. A total of 122 patients were diagnosed with colon adenocarcinoma between 2010 and 2019. PD-L1+ (clone 22C3) “macrophage scores” in the microenvironment of cancer gland rupture were calculated. The effects of these variables on prognosis were statistically analyzed. CD163+ TAMs were denser in the cancer gland rupture microenvironment. PD-L1+ TAMs were observed in the tumor periphery, and there was a significant difference between the rates of PD-L1 expression in TAMs and survival time (log-rank = 10.46, P = 0.015), clinical stage 2 (P = 0.038), and primary tumor 3 and primary tumor 4 cases (P = 0.004, P = 0.013). The risk of mortality was 4.070 times higher in patients with a PD-L1 expression rate of ≥1% in CD163+ TAMs. High PD-L1 expression in CD163+ TAMs is associated with poor overall survival. Therefore, blocking PD-L1 in CD163+ TAMs can be used as a target for immunotherapy.