CD169-positive sinus macrophages in the lymph nodes determine bladder cancer prognosis.

CD169 macrophages are suggested to play a pivotal role in establishing anti-tumor immunity. They capture dead tumor cell-associated antigens and transfer their information to lymphocsytes, including CD8 T cells, which is important for successful tumor suppression. This study aimed to determine the prognostic significance of CD169 macrophages residing in the tumor-draining lymph nodes from cases of bladder cancer. In this retrospective study, 44 bladder cancer patients who received radical cystectomy were examined. The abundance of CD169 macrophages in the regional lymph nodes and the number of CD8 T cells in the primary tumor were investigated by immunohistochemistry. A CD169 score was calculated based on the intensity of CD169 staining and the proportion of CD169 macrophages, and the scores were compared to the patients' clinicopathological parameters. A high CD169 score was significantly associated with low T stage and with a high number of CD8 T cells infiltrating into the tumor. The group with high CD169 expression had significantly longer cancer-specific survival than the group with low CD169 expression (5-year cancer-specific survival rate: 83.3% vs 31.3%). In a multivariate analysis, the CD169 score was identified as a strong and independent favorable prognostic factor for cancer-specific survival. Our findings suggest that CD169 macrophages in the lymph nodes enhance anti-tumor immunity by expanding CD8 T cells in bladder cancer. The CD169 score may serve as a novel marker for the evaluation of bladder cancer prognosis.