Posted: Friday, March 24, 2023
According to a meta-analysis published in Frontiers in Oncology, a high density of alternatively activated phenotype (M2 type) tumor-associated macrophages appears to be a reliable predictor of adverse outcomes for patients with diffuse large B-cell lymphoma (DLBCL). In addition, the association between M2 tumor-associated macrophages and patient outcome was found to be affected using rituximab. Lin et al, of Qingdao University, China, and colleagues aimed to elucidate the role of tumor-associated macrophages in the progression of DLBCL as well as their prognostic value.
The meta-analysis reviewed 23 studies of 2,992 patients with DLBCL. All included studies used immunohistochemical or immunofluorescence staining to detect tumor-associated macrophages. The included studies were published between 2011 and 2022 and had between 36 and 430 participants.
Of the eligible studies that reported an association between the density of CD68-positive tumor-associated macrophages and overall or progression-free survival, no significant correlation was observed between total the density of these cells and overall survival (hazard ratio [HR] = 0.929, 95% confidence interval [CI] = 0.607–1.422; P = .734), with significant heterogeneity or progression-free survival with significant heterogeneity. The results of 14 of the eligible studies demonstrated a correlation between a high density of M2 tumor-associated macrophages in the microenvironment with unfavorable overall survival (HR = 1.750, 95% CI = 1.188–2.579; P = .005), with significant heterogeneity.
Moreover, pooled hazard ratios from nine studies demonstrated that a high density of M2 tumor-associated macrophages was not significantly associated with poor progression-free survival (HR = 1.672, 95% CI = 0.864–3.237; P = .127), with evident heterogeneity. A high density of M2 tumor-associated macrophages was significantly associated with unfavorable overall survival (HR = 2.620, 95% CI = 1.232–5.572; P = 0.012) and progression-free survival (HR = 3.475, 95% CI = 1.210–9.985; P = 0.021) in a subgroup analysis of patients whose treatment regimen contained rituximab.
Disclosure: The study authors reported no conflicts of interest.