Prognostic role of high B7-H4 expression in patients with solid tumors: a meta-analysis.

Background: Recently, many studies have shown that B7-H4 exhibits altered expression in various cancers. We performed a meta-analysis to evaluate the prognostic role of B7-H4 expression in solid tumors. Results: Data from 18 observational studies and 2467 patients were summarized. An elevated baseline B7-H4 was significantly associated with worse OS (pooled HR = 1.79; 95% CI = 1.56-2.06). Differences across subgroups of tumor type, patients' ethnicity, analysis type, HR obtain method and cut-off value were not significant (P-D = 0.313, P-D = 0.716, P-D = 0.896, P-D = 0.290 and P-D = 0.153, respectively). Furthermore, patients with high B7-H4 had a significantly shorter DFS (pooled HR = 2.12; 95% CI = 1.45-3.09). Materials and Methods: We searched PubMed, Embase and the Cochrane Library (last update by November 26, 2015) to identify studies assessing the effect of B7-H4 on survival of cancer patients. Pooled hazard ratios (HRs) for overall survival (OS) and disease-free survival (DFS) were estimated using fixed-effects models and random-effects models respectively. Conclusions: This meta-analysis clarified that high B7-H4 expression in tissue was significantly associated with poor survival in patients with solid tumors. Future clinical studies are warranted to determine whether B7-H4 blockade has a favorable effect on disease recurrence and mortality.