Prognostic Value of β-catenin Expression in Breast Cancer Patients: a Meta-analysis.

Background: β-catenin plays a crucial role in the progression of breast cancer (BC) and a prognostic role of in BC patients has been widely reported. However, controversy still remains.

Methods: Identical search strategies were used to search relevant literature in electronic databases updated to July 1, 2014. Individual hazard ratios (HRs) and 95% confidence intervals (CIs) were extracted and pooled HRs with 95%CIs were used to evaluate the strength of association between positive β-catenin expression in different subcellular locations and survival results of BC patients. Subgroup and meta-regression analyses were performed to explore heterogeneity. Funnel plots of Begg's and Egger's linear regression test were used to investigate publication bias. Heterogeneity and sensitivity were also assessed. All the work was completed using STATA.

Results: A total of 2,204 patients from 12 evaluative studies were finally included. Pooled HRs and 95%CIs suggested that β-catenin expression in cytoplasm/nucleus had an unfavorable impact on both overall survival (OS) (HR: 1.93, 95%CI: 1.40-2.65) and disease free survival (DFS)/ recurrent free survival (RFS) (HR: 1.60, 95%CI: 1.20-2.13) in BC patients. However, here was no significant association between β-catenin expression in the membranes with OS (HR: 0.65, 95%CI: 0.42-1.02) or DFS/RFS (HR: 0.66, 95%CI: 0.38-1.13). Publication bias was absent in all of the four outcomes. Sensitivity analysis revealed that the results of this meta-analysis were robust.

Conclusions: Positive β-catenin expression in cytoplasm/nucleus rather than in membrane is a significant prognostic factor in patients with BC who have been surgically treated.