Prognostic significance of CD169‐positive lymph node sinus macrophages in patients with endometrial carcinoma

Lymph node (LN) macrophages play critical roles in anti‐tumor immunity, which develops via the activation of cytotoxic T cells (CTL) and NK cells. The present study aims to determine the prognostic significance of CD169(+) LN macrophages in patients with endometrial carcinoma (EC). The number of CD169(+) cells or the CD169(+)‐to‐CD68(+) macrophage ratio in regional LN (RLN), and the number of CD8(+) CTL or CD57(+) NK cells in tumor tissues were investigated by immunohistochemistry in paraffin‐embedded tissue samples from 79 patients with EC. A high density of CD169(+) cells in the RLN of patients with EC was correlated with an early clinical stage or no LN metastasis. A high number of CD169(+) cells and a high CD169(+)‐to‐CD68(+) macrophage ratio were significantly associated with longer overall survival in EC. We also found that the density of CD169(+) macrophages was positively correlated with the number of CD8(+) CTL and CD57(+) NK cells that infiltrated into tumor tissues. A high density of CD57(+) cells in EC tissues was associated with a better prognosis, while a high density of CD8(+) cells was not linked to an altered prognosis. The present study showed that the density of CD169(+) macrophages in RLN was associated with an improved prognosis in EC patients. CD169(+) macrophages in RLN might represent a useful marker for assessing clinical prognoses and monitoring anti‐tumor immunity in patients with EC.