β-catenin Overexpression in the Nucleus Predicts Progress Disease and Unfavourable Survival in Colorectal Cancer: A Meta-Analysis

BACKGROUND: β-catenin plays a key role in the progression of colorectal cancer (CRC). However, its prognostic significance for patients with CRC remains controversial. METHODOLOGY: Identical search strategies were used to search relevant literatures in the PubMed, Embase and Web of Science databases. The correlation between β-catenin expression and clinicopathological features and prognosis was analyzed. PRINCIPAL FINDINGS: A total of 18 studies met the inclusion criteria, which comprised 3665 cases. Meta-analysis suggested that β-catenin overexpression in the nucleus was significantly associated with disease free survival (DFS) (n = 541 in 3 studies; HR = 1.87, 95% CI: 1.28–2.71; Z = 3.26; P = 0.001) and overall survival (OS) for CRC patients (n = 2630 in 10 studies; HR = 1.55, 95% CI: 1.12–2.14; Z = 2.62; P = 0.009). However, there was no significant association between β-catenin expression in the cytoplasm and OS (n = 1327 in 3 studies; HR = 1.04, 95% CI: 0.88–1.24, Z = 0.46, P = 0.643). The combined odds ratio (OR) of β-catenin in the nucleus indicated that β-catenin overexpression was associated with advanced stage CRC (n = 950 in 7 studies; OR = 0.71, 95% CI: 0.53–0.94; Z = 2.35; P = 0.019) and metastasis of CRC (n = 628 in 5 studies; OR = 0.49, 95% CI: 0.25–0.96, Z = 2.06, P = 0.039). β-catenin overexpression in the nucleus had no correlation with the tumor site (colon or rectum), differentiation grade, lymph node status or depth of invasion. The pooled ORs were 1.09 (95% CI: 0.41–2.91, Z = 0.18, P = 0.856), 1.27(95% CI: 0.76–2.10, Z = 0.92, P = 0.357), 0.71(95% CI: 0.46–1.09, Z = 1.58, P = 0.115) and 0.82(95% CI: 0.4–1.68, Z = 0.53, P = 0.594). CONCLUSIONS: This study showed that β-catenin overexpression in the nucleus, rather than in the cytoplasm, appeared to be associated with progress disease and a worse prognosis for CRC patients.