Prognostic significance of tumor-infiltrating lymphocytes and macrophages in nasopharyngeal carcinoma: a systematic review and meta-analysis.

Abstract

Many studies have investigated the prognostic value of tumor-infiltrating lymphocytes (TILs) and tumor-infiltrating macrophages (TIMs) in patients with nasopharyngeal carcinoma (NPC), but the results remain controversial. Here, we performed a meta-analysis to evaluate the prognostic significance of TILs/TIMs in patients with NPC METHODS: The study was registered with PROSPERO (CRD42021234078). PubMed, Embase, and Web of Science databases were searched up to Dec 30, 2020. We reviewed studies that evaluated the relationship between TILs/TIMs and overall survival (OS), disease-free survival (DFS), or progression-free survival (PFS) in NPC. For TILs, CD3, CD4, CD8, and FOXP3 were searched as T-cell markers, CD19 and CD20 as B-cell markers, and CD56 as a natural killer cell marker. For TIMs, CD68 and CD163 were searched as total and M2 macrophage markers, respectively. In total, 19 studies with 3708 NPC were included in this meta-analysis. We found that high total numbers of TILs were significantly associated with favorable OS [hazard ratio (HR) 0.46, 95% confidence interval (CI) 0.38-0.57 and PFS (HR 0.48, 95% CI 0.38-0.62)]. In contrast, tumor infiltration by CD3+ T cells (HR 0.55, 95% CI 0.39-0.76), CD4+ T cells (HR 0.40, 95% CI 0.18-0.85), and CD8+ T cells (HR 0.56, 95% CI 0.34-0.93) correlated positively with OS. No significant relationship was found between survival and tumor infiltration by FOXP3+ T cells, CD68+ macrophages, or CD163+ macrophages. Our findings revealed that tumor infiltration by CD3+ , CD4+ , and CD8+ T cells could be prognostic biomarkers in NPC.