Prognostic significance of tumor-associated macrophages in patients with nasopharyngeal carcinoma: A meta-analysis

BACKGROUND: To explore the prognostic value of diverse subsets of tumor-associated macrophages (TAMs) in prognosis in patients with nasopharyngeal carcinoma (NPC) using meta-analysis. METHODS: Relevant studies were searched in the database of PubMed, Web of Science, Embase, Cochrane Library, Scopus, China National Knowledge Infrastructure (CNKI), and Wanfang till November 2019. The relationship between TAMs and survival outcomes was estimated by pooling hazard ratios (HRs) and 95% confidence intervals (CIs); and the correlation of TAMs and clinicopathological factors was evaluated by using odds ratios (ORs) and 95%CIs. RESULTS: Six studies with 1549 patients were included in this meta-analysis. The high expression of CD68+ TAMs was associated with favorable disease-free survival (DFS) (HR = 0.66, 95%CI = 0.50–0.88, P = .005), whereas the density of M2-like TAMs (CD163+, CD68+CCL18+, and CD206+) was correlated to poor overall survival (OS) (HR = 1.77, 95%CI = 1.22–2.56, P = .003) and DFS (HR = 1.96, 95%CI = 1.00–3.85, P = .050) in patients with NPC. CONCLUSIONS: CD68+ TAM density is associated with superior DFS, while CD163+ M2-like TAMs predicted poor prognosis in patients with NPC.