CSF-1R expression in tumor-associated macrophages is associated with worse prognosis in classical Hodgkin lymphoma

Objectives: The aim of this study was to determine the prognostic relevance of colony-stimulating 1 receptor (CSF-1R) expression in both Hodgkin/Reed-Sternberg (HRS) cells and the surrounding cells (non-HRS cells) in patients with classical Hodgkin lymphoma (CHL). Methods: Diagnostic tissues from 112 patients with CHL treated with doxorubicin, bleomycin, vinblastine, and dacarbazine were evaluated retrospectively by immunohistochemical analysis for CSF-1R and CD68 and CD 163 for tissue-associated macrophages. Results: High numbers (≥30%) of non-HRS cells expressing CSF-1R conferred inferior event-free survival and overall survival in univariate and multivariate analysis. High numbers of non-HRS cells expressing CSF-1R were significantly associated with a high number of tumor-associated macrophages as detected by CD163 expression (P < .001). In particular, coexpression of CSF-1R and CD163 was associated with a worse survival outcome than either CSF-1R or CD163 expression alone or no expression. Conclusions: Our data demonstrate that a high number of non-HRS cells expressing CSF-1R are correlated with an increased tumor macrophage content and worse survival.