The prognostic relevance of tumor associated macrophages in advanced stage classical Hodgkin lymphoma

Although the treatment of Hodgkin lymphoma (HL) has been improved, distinguishing reliable prognostic biomarkers could better stratify patients for more effective treatment. We analyzed the prognostic relevance of CD68+ tumor-associated macrophages (TAMs) by immunohistochemical analysis at diagnosis and standard clinical parameters in 52 ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine)-treated patients with advanced stage classical HL (cHL). Patients with >25% CD68+ TAMs compared to those with ≤25% had worse 5-year overall survival (45% vs. 77%, log-rank p = 0.019) and showed a trend toward shorter 5-year event-free survival (51% vs. 71%, log-rank p = 0.19). Additionally, no significant correlation with selected clinical features was found. Significantly shorter 5-year overall survival was associated with International Prognostic Score (IPS) >2, bulky disease, elevated erythrocyte sedimentation rate (log-rank test, p = 0.003, p = 0.049, p = 0.007, respectively). In multivariate analysis, increased CD68+TAMs, IPS >2, and bulky disease were identified as independent prognostic factors for overall survival (Cox multivariate model, p = 0.006, p = 0.007, p = 0.013, respectively). Tumor-associated macrophages represent a potential prognostic biomarker which could contribute to better risk stratification of patients with cHL.