Abstract
BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) exhibits heterogeneous clinical outcomes, including variations in event-free survival (EFS). Tumor microenvironment (TME) components, particularly absolute monocyte count (AMC), tumor-associated macrophages (TAMs), and tumor-infiltrating lymphocytes (TILs) have been implicated in prognosis, although findings remain inconsistent. This study evaluates the prognostic value of AMC, TAMs (CD163), and TILs (CD8) on two-year EFS in DLBCL patients treated with R-CHOP. METHODS: A retrospective cohort study of 108 DLBCL patients treated from January 2014 to March 2021 was conducted. AMC was obtained from peripheral blood, while CD163 and CD8 expressions were analyzed via immunohistochemistry. Associations with two-year EFS were assessed using hazard ratios (HR), and correlations between AMC and tissue immune markers were evaluated. RESULTS: High AMC and CD163 expression were significantly associated with poorer two-year EFS (HR = 9.82 and 8.57; both p < 0.001), whereas elevated CD8 expression predicted better outcomes (HR = 0.13; p < 0.001). AMC positively correlated with CD163 (r = 0.577; p < 0.001) and negatively with CD8 (r = -0.599; p < 0.001). CONCLUSION: AMC and CD163 are negative prognostic markers, while CD8 is protective. AMC may reflect the immune profile of the TME and serve as a practical prognostic biomarker in DLBCL.