INCREASED SERUM 72 KDA METALLOPROTEINASE IN SEROUS OVARIAN-TUMORS - COMPARISON WITH CA-125

72 KDa metalloproteinase (MMP-2) is an enzyme present in neoplastic ce lls and also in normal fibroblasts. It specifically cleaves type IV co llagen, and therefore may play a critical role in tumor invasion and m etastasis mechanisms. The aim of the present study was to determine se rum levels of MMP-2 in serous ovarian tumors, and compare these with s erum levels of CA 125. Ten primary ovarian serous cystadenocarcinomas, 5 borderline tumors, and 10 serous cystadenomas, all treated with pri mary surgery, were recruited from our series of serous ovarian tumors, and studied. Patients, serum samples were obtained before surgery, an d the MMP-2 levels were measured by the substrate capture enzyme-linke d immunosorbet assay. The analysis of serum MMP-2, gave values signifi cantly higher in cystadenocarcinomas than in borderline tumors and cys tadenomas (one way analysis of variance, P < 0.001); in particular, se rum MMP-2 was significantly correlated to the MMP-2 immunostaining of the tumor (Spearman correlation, r = 0.82, and P < 0.001). An arbitrar y cutoff of the median value of normal adult female samples (0.22 unit s) was chosen and all except for one patient with cystadenocarcinoma w as shown to have serum MMP-2 levels above the cutoff value, with 90% s ensitivity, 70% specificity, and a 75% positive predictive value (50% of Cohen's Kappa); on the other hand, CA 125 showed 80% sensitivity, a nd a 73% positive predictive value. The association of serum MMP-2 wit h CA 125 increased sensitivity to 100% in patients with cystadenocarci noma, with 70% persisting specificity and a 77% positive predictive va lue (54% of Cohen's Kappa). Serum MMP-2 levels were found to be signif icantly increased in patients with cystadenocarcinoma in comparison wi th borderline tumors and cystadenomas, showing a direct relationship w ith tissutal MMP-2 expression in serous ovarian tumors. Although our r esults were preliminary, they clearly suggested that serum MMP-2 may b e an interesting diagnostic marker for cystadenocarcinomas.