Prognostic value of serum alpha-fetoprotein levels in patients with gastric cancer: a meta-analysis

Background To investigate the prognostic value of pre-treatment serum alpha-fetoprotein (AFP) levels in patients with gastric cancer (GC). Methods PubMed, EMBASE, Medline and Web of Science databases were systematically searched for studies published between January 01, 1998 and December 31, 2018 that investigated the relationship between pre-treatment serum AFP levels and prognosis of patients with GC. Hazard ratios (HR) for overall survival (OS), disease-free survival (DFS), and their corresponding 95% confidence intervals (CIs) were evaluated. Results 13 studies involving 9099 patients with GC were included in the meta-analysis. High pre-treatment serum AFP levels were significantly associated with poor outcome in patients with GC. Although there was significant heterogeneity between studies, sub-group analyses found that studies of 'non-China' countries, sample size <500, mixed treatment, or AFP cut-off value >= 20 ng/ml, had low heterogeneity. Conclusions The pooled analysis suggests that pre-treatment serum AFP levels can be used as a prognostic indicator in patients with GC. Further research is required to confirm these results.