β-catenin overexpression in the nucleus predicts progress disease and unfavourable survival in colorectal cancer: a meta-analysis.

Background: b-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 b-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 b-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 b-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 b-catenin in the nucleus indicated that b-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). b-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 b-catenin overexpression in the nucleus, rather than in the cytoplasm, appeared to be associated with progress disease and a worse prognosis for CRC patients.