CD169+ Macrophages Residing in the Draining Lymph Nodes and Infiltrating the Tumor Play Opposite Roles in the Pathogenesis of Bladder Cancer

Abstract

Purpose: CD169+ macrophages are considered to enhance anti-tumor immunity by capturing lymph-borne dead tumor cells. The number of CD169+ macrophages in regional lymph nodes (RLNs) is positively correlated with prolonged cancer-free survival in various human cancers. However, a recent study argued against this dogma; that is, CD169+ macrophages infiltrating into the tumor were associated with poor prognosis in patients with breast cancer. To explain this discrepancy, we quantified the number of CD169+ macrophages located in the bladder tumor and RLNs of the same patients and examined their relationship with the 5-year survival rate. Patients and Methods: Tumor and RLN specimens resected from 40 invasive bladder cancer patients (29 males and 11 females; median age, 70.7 years; range, 49–81 years) who underwent radical cystectomy were evaluated using immunostaining. Results: The number of CD169+ macrophages in RLNs was associated with a good cancer prognosis, while CD169+ macrophages infiltrating the tumor strongly correlated with a higher incidence of lymphovascular invasion. Conclusion: CD169+ macrophages play opposing roles in the induction of anti-tumor immunity based on their location in RLNs or tumors.