Clinicopathologic Significance and Prognostic Value of B7 Homolog 1 in Gastric Cancer: A Systematic Review and Meta-Analysis

Immunologic checkpoint marker B7 homolog 1 (B7-H1) plays a fundamental role in the initiation and progression of gastric cancer (GC); however, the clinicopathologic significance and prognostic value of B7-H1 in GC remains controversial. In this study, we aimed to assess their relationship through a meta-analysis. Medline/PubMed, EMBASE, the Cochrane Library databases, and Grey literature were searched up to August 10, 2015, for eligible studies of the association between B7-H1 expression and overall survival in GC. The hazard ratio and its 95% confidence interval (CI) were calculated from the included studies. Moreover, the odds ratio (OR) was also extracted to evaluate the association between the clinicopathologic parameters of participants and B7-H1 expression. Five studies involving 481 patients were included in the meta-analysis. The pooled results showed that positive B7-H1 expression was a negative predictor for overall survival with hazard ratio of 1.74 (95% CI: 1.40–2.17; P(heterogeneity) = 0.146) in GC. Additionally, increased B7-H1 was found to be significantly associated with positive lymph node metastasis (OR = 2.61, 95% CI: 1.78–3.84; P(heterogeneity) = 0.004) and poorer tumor stage (OR = 2.28, 95% CI: 1.39–3.74; P(heterogeneity) = 0.006); however, higher B7-H1 expression was not significantly correlated with poorer tumor differentiation (OR = 1.29, 95% CI: 0.90–1.86; P(heterogeneity) = 0.013) and bigger tumor size (OR = 1.18, 95% CI: 0.81–1.73; P(heterogeneity) = 0.104). The meta-analysis suggested that B7-H1 could act as a significant biomarker in the poor prognosis of gastric carcinoma.