Background: Evidence suggests that CD204-positive (CD204(+)) tumor-infiltrating macrophages are associated with aggressive behavior of various cancers; however, the clinical, pathological, and prognostic associations of tumor-infiltrating CD204(+) macrophages in urothelial cancer have not been reported.
Methods: A tissue microarray was constructed from the centers and peripheries of 171 upper urinary tract cancers treated with nephroureterectomy. CD204 immunohistochemistry was performed. The density of CD204(+) cells was calculated using image analysis software, and survival analyses were performed using the Kaplan-Meier method and multivariate Cox proportional hazards regression models.
Results: High CD204(+) cell density at the centers and peripheries of tumors was significantly associated with several adverse prognostic factors, including sessile architecture, histological high-grade, presence of lymphovascular invasion, concomitant carcinoma in situ, higher tumor stage, and lymph node metastasis. High CD204(+) cell density was significantly associated with shorter metastasis-free and cancer-specific survival (log-rank p < 0.001) and shorter metastasis-free survival in multivariate analysis.
Conclusions: A high density of tumor-infiltrating CD204(+) macrophages was associated with aggressive behavior of upper urinary tract cancer. Our results suggest that a specific immune microenvironment may be associated with the biological behavior of urothelial cancer and that CD204 may serve as a novel prognostic biomarker for these tumors.