Introduction: Tumor-associated macrophages (TAM) play a dual role in the development of gastric cancer (GC). This study aims to analyze the prognostic value of TAM density in GC patients.
Evidence acquisition: We conducted a meta-analysis of 11 studies (N.=1043) to investigate the correlation between TAM density and the overall survival (OS) or disease free survival (DFS) of GC patients. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated by the STATA statistical software.
Evidence synthesis: The HR of OS of GC patients with high-density TAM is 1.56 (95% CI: 0.90~2.22, P<0.001) as compared with those with low-density TAM, and that of DFS is 1.10 (95% CI: 0.16~2.03, P=0.022), indicating that TAM density does not significantly predict the poor survival of GC. A subgroup analysis by ethnicity also revealed no significance effect between TAM density and a worse OS among both Asians and Caucasians (Asians: HR=1.47, 95% CI: 0.76~2.18, P<0.001; Caucasians: HR=2.23, 95% CI: 0.62~3.84, P=0.007, respectively).
Conclusions: Our findings provide empirical evidence that TAM density is not an independent predictor for the survival of GC patients.