Abstract
BACKGROUND AND AIMS: There are still no useful biomarkers for the prognosis of esophageal squamous cell carcinoma (ESCC). In the prognosis of some kinds of cancer, soluble programmed death 1 (sPD-1) and programmed death ligand 1 (sPD-L1) have demonstrated statistical significance, but the prognostic value of serum sPD-L1 and sPD-1 remains unclear in ESCC. METHODS: Here, a meta-analysis was performed to estimate the prognostic value of sPD-L1 and sPD-1 in ESCC. To obtain eligible studies, we searched mainstream databases (PubMed, Cochrane, Embase, Web of Science, Wanfang Data, and CNKI), and the survival data including hazard ratios (HR) and its 95% confidence intervals (95% CI) from included literature were extracted. RESULTS: Six articles were included, including 645 patients with ESCC. The statistical result of this meta-analysis indicated that serum sPD-1 had no significant correlation with overall survival (OS) of patients with ESCC (p > 0.05). Patients with ESCC with high concentrations of serum sPD-L1 demonstrated a significantly poor prognosis (HR = 1.73, 95% CI: 1.42-2.11, p < 0.001). CONCLUSION: Higher levels of serum sPD-L1 may predict poor OS in ESCC patients, which may be a promising and credible prognostic biomarker for esophageal cancer.