Fig. 4

Forest plots and funnel plots demonstrating the associations between PDCD4 expression and overall survival (OS) of patients with solid tumors. a Forest plot shows that low PDCD4 expression level is significantly associated with a low OS rate. In total, 20 studies from 10 papers were included. Two T subcategories of gastric cancer were reported by Guo et al.: Guo [7] (01) for pT2a gastric cancer and Guo [7] (02) for pT2b gastric cancer. Two sites of PDCD4 expression were reported by Nagao et al.: Nagao [15] (01) for PDCD4 expression in nucleus and Nagao [15] (02) for PDCD4 expression in cytoplasm of pancreatic cancer cells. Different Duke’s stages were reported by Horiuchi et al.: Horiuchi [31] (01) for Duke’s stage B, Horiuchi [31] (02) for Duke’s stage C, and Horiuchi [31] (03) for Duke’s stage D colorectal cancer in multivariate analysis; Horiuchi [31] (04) for Duke’s stage B, Horiuchi [31] (05) for Duke’s stage C, and Horiuchi [31] (05) for Duke’s stage D colorectal cancer in univariate analysis. A fixed effects model was used to calculate the pooled hazard ratio (HR) for OS. Significant associations are observed in univariate model and in multivariate model. b Funnel plot shows no evidence of publication bias among papers on the association between PDCD4 expression and overall survival rate of various types of cancer. s.e. standard error. The P value is 0.940 in Begg’s test and is 0.744 in Egger’s test