Does overexpression of HER-2 correlate with clinicopathological characteristics and prognosis in colorectal cancer? Evidence from a meta-analysis

BACKGROUND: Previous studies have been inconsistent with respect to the reported associations between human epidermal growth factor receptor (HER-2/neu) overexpression in colorectal cancer. The aims of this meta-analysis are to assess its correlation with clinicopathological characteristics and prognostic significance in colorectal cancer. METHODS: Eligible studies were searched in Pubmed, Embase and Web of Science databases. The inclusion criteria were studies that assessed the relationship between HER-2 expression detected by immunohistochemistry (IHC) and the prognosis or clinicopathological features in patients with colorectal cancer (CRC). Subgroup analysis according to sex, tumor location, TNM stage, grade of differentiation and lymph node metastasis were produced. Odds ratio (OR) or hazard ratio (HR) with 95 % confidence interval (CI) were calculated to examine the risk or hazard association, and heterogeneity and publication bias analyses were also performed. RESULTS: A total of 18 studies comprising 2867 colorectal cancer patients were included to assess the association between HER-2 immunohistochemical expression and clinicopathological characteristics and survival. The overall analysis showed that there was no detectable relation between HER-2 expression and prognosis in colorectal cancer patients with the pooled HR of 1.08 (95 % CI: 0.96–1.21, P = 0.21). With respect to clinicopathological features, there was also no detectable relation between HER-2 expression and sex (OR = 0.91, 95 % CI: 0.72–1.15, P = 0.42), tumor location (OR = 1.21, 95 % CI = 0.88–1.65, P = 0.24), grade of differentiation (OR = 1.03, 95 % CI = 0.72–1.47, P = 0.86), TNM stages (OR = 0.72, 95 % CI = 0.31–1.66, P = 0.44), or lymph node metastasis (OR = 1.90, 95 % CI = 0.90–4.02, P = 0.09) in CRC. CONCLUSIONS: The finding from this present meta-analysis suggested that HER-2 overexpression was not related to clinicopathological characteristics and poor prognostic of colorectal cancer patients.