Matrix metalloproteinase 2 overexpression and prognosis in colorectal cancer: a meta-analysis

Many studies investigated the relationship between matrix metalloproteinase 2 (MMP-2) overexpression and survival in patients with colorectal cancer (CRC), but yielded inconsistent results. To derive a more precise estimate of the prognostic significance of MMP-2 overexpression, we reviewed published studies and carried out a meta-analysis. Eligible articles were identified for the period up to March 2012 in electronic databases. To evaluate the correlation between MMP-2 overexpression and the prognosis in CRC, pooled hazard ratio (HR) and its 95 % confidence interval (95 % CI) for poorer overall and progression-free survival were appropriately derived from fixed-effects or random-effects models using standard meta-analysis techniques. Thirteen studies with a total of 1,919 CRC patients stratifying overall survival (OS) and/or progression-free survival in CRC patients by MMP-2 expression status were eligible for analysis. Ten studies investigated the OS in a total of 1,612 cases with CRC, and five studies investigated the progression-free survival in a total of 508 patients CRC. The combined HR estimate for OS and progression-free survival was 1.74 (95 % CI, 1.34-2.26) and 1.35 (95 % CI, 1.07-1.80), respectively. Both subgroup analyses and sensitivity analysis further identified the prognostic role of MMP-2 overexpression in patients with CRC. There was no evidence for publication bias. In conclusion, MMP-2 overexpression is associated with poorer overall and progression-free survival in patients with CRC.