Plasma matrix metalloproteinase 9 as an early surrogate biomarker of advanced colorectal neoplasia

Introduction: Matrix metalloproteinases (MMPs) are overexpressed at different stages of colorectal carcinogenesis and could serve as early surrogate biomarkers of colorectal neoplasia. Objective: To assess the utility of plasma MMP2 and MMP9 levels in the detection of advanced colorectal neoplasia and their correlation with tissue levels. Methods: We analysed blood and tissue samples from patients with non-advanced adenomas (n=25), advanced adenomas (n=25), colorectal cancer (n=25) and healthy controls (n=75). Plasma and tissue gelatinase levels were determined by Luminex XMAP technology and gelatin zymography. Receiver operating characteristic (ROC) curve analysis was used to calculate the optimum cut-off for the detection of advanced colorectal neoplasia. Results: Plasma MMP2 levels were similar between groups whatever the type of lesion. Plasma MMP9 levels were significantly higher in patients with neoplastic lesions than in healthy controls (median 292.3 ng/ml vs. 139.08 ng/ml, P<0.001). MMP9 levels were also higher in colorectal cancer than in non-advanced adenomas (median 314.6 ng/ml vs. 274.3 ng/ml, P=0.03). There was a significant correlation between plasma and tissue levels of MMP9 (r = 0.5, P<0.001). The plasma MMP9 cut-off range with the highest diagnostic accuracy was between 173 ng/ml and 204 ng/ml (AUC = 0.80 [95% CI: 0.72-0.86], P<0.001; sensitivity, 80-86% and specificity, 57-67%). Conclusion: Plasma MMP9 could be a surrogate biomarker for the early detection of advanced colorectal neoplasia, although its diagnostic performance could be increased by combination with other biomarkers. (C) 2015 Elsevier Espana, S.L.U., AEEH y AEG. All rights reserved.