CD163+ macrophages predict a poor prognosis in patients with primary T1 high-grade urothelial carcinoma of the bladder.

PURPOSE: Macrophages are a major cell type that can infiltrate solid tumors and exhibit distinct phenotypes in different tumor microenvironments. This study investigates the prognostic value of tumor-infiltrated CD163+ macrophages in patients with T1 high-grade (T1HG) bladder cancer. METHODS: CD163+ macrophages were assessed by immunohistochemistry in 94 T1HG bladder cancer samples. Kaplan-Meier analyses and Cox proportional hazards' regression models were applied to evaluate recurrence-free survival, progression-free survival and disease-specific survival. RESULTS: With a median follow-up of 60 months, 37 (39.4%) patients experienced disease recurrence, 14 (14.9%) progression, 11 (11.7%) disease-specific mortality. High CD163+ macrophages were associated with higher risk of disease recurrence and progression (P < 0.05, for both). In multivariate Cox proportional hazards regression analysis, high CD163+ macrophages were a significant negative predictor of recurrence-free survival, progression-free survival and disease-specific survival (P < 0.05 for all). CONCLUSION: CD163+ macrophages are a poor prognostic factor in T1HG bladder cancer. This finding provide the ground for further testing it in predicting the outcome of this challenging disease.