Unfavorable Prognostic Value of Human Kallikrein 7 Quantified by ELISA in Ovarian Cancer Cytosols

Human tissue kallikrein 7 (gene, KLK7; protein, hK7) is a member of the kallikrein family of secreted serine proteases. Reports indicate that in ovarian cancer, KLK7 is significantly up-regulated at the mRNA level. The aim of this study was to determine whether hK7, measured quantitatively by ELISA in ovarian cancer cytosols, is a prognostic biomarker for ovarian cancer. We used a newly developed ELISA with 2 monoclonal antibodies to quantify hK7 production in 260 ovarian tumor cytosols and correlated these data with various clinicopathologic variables and patient outcomes [progression-free survival (PFS) and overall survival (OS)] over a median follow-up period of 52 months. Median (range) hK7 concentration in ovarian tumor cytosols was 2.84 (0-32.8) ng/mg of total protein. Compared with healthy and benign ovarian tissues and nonovarian tumors that metastasized to the ovary, malignant ovarian tumor cytosols highly overproduced hK7 (P