Prognostic significance of MMP-7 expression in colorectal cancer: a meta-analysis

Matrix metalloproteinase-7 (MMP-7) is a member of the family of matrix metalloproteinases (MMPs); it is associated with invasive tumor growth and distant metastasis in colorectal cancer (CRC). However, the prognostic value of MMP-7 in CRC remains controversial. Thus, we conducted a meta-analysis to investigate the prognostic value of MMP-7 expression in CRC.

We systematically searched for studies evaluating the relationship between MMP-7 expression and the outcome of CRC patients in PubMed, the Cochrane library, Embase, Google Scholar, and Wanfang databases updated to August 2014. Studies were assessed for quality using REMARK (REporting recommendations for tumor MARKer prognostic studies). Hazard ratios (HRs) with 95% confidence intervals (95%CIs) were pooled to estimate the hazard for overall survival (OS) and disease-free survival (DFS), and odds ratios (ORs) with 95%CIs were pooled to estimate the impact of MMP-7 on the 5-year survival rate.

In total, 2985 patients from 17 studies were included in this meta-analysis. Our results showed that MMP-7 over-expression predicted poor OS (HR=3.57, 95%CI 2.21-5.75, P=0.000, random-effect model), poor DFS (HR=2.49, 95%CI 1.73-3.57, P=0.000, fixed-effect model), and decreased 5-year survival rate (OR=0.26, 95%CI 0.19-0.37, P=0.000, fixed-effect model). Therefore, MMP-7 is an indicator of poor survival and high recurrence rate in CRC patients.

MMP-7 can serve as a prognostic indicator and a potential novel target for treatment in CRC patients. More well-designed prospective studies with better methodology for MMP-7 assessment are required to clarify the prognostic significance of MMP-7 expression in CRC patients.