The objective of this article is to study the correlation between plasma levels of matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9) and multisteps of cervical carcinogenesis as well as to evaluate their clinical application. Two hundred one blood samples were collected from 52 patients with early cervical squamous cell carcinoma (SCC), 41 with high-grade cervical intraepithelial neoplasia (CIN), 27 with low-grade CIN, and 81 healthy individuals. Enzyme-linked immunosorbent assay was used to detect plasma MMP-2 and MMP-9 concentrations. Gelatin zymography was used to directly compare the activities of MMP-2 and MMP-9 and to measure the MMP-9:MMP-2 ratio. A receiver-operating characteristic curve was plotted to determine the plasma cutoff levels of these biomarkers. Patients with low- and high-grade CIN were found to have significantly different plasma MMP-9 levels (P < .001) but not MMP-2 levels. The cutoff values of 103.8 ng/mL for plasma MMP-9 and 0.70 for the MMP-9:MMP-2 ratio were used to distinguish SCC and high-grade CIN from low-grade CIN and healthy cases. The sensitivities and negative predictive values of these cutoff points were high (75.6% and 75.8% for MMP-9; 79.6% and 79.8% for the MMP-9:MMP-2 ratio). A significant elevation of plasma MMP-9 levels and the MMP-9:MMP-2 ratio in high-grade CIN and SCC patients manifests a stage point of high-grade CIN in cervical carcinogenesis and can be used as additional molecular information. Once plasma MMP-9 levels fall below 103.8 ng/mL or the MMP-9:MMP-2 ratio falls below 0.70, patients have only about a 20% chance of developing these cervical lesions.
