Evaluation of serum procathepsin B, cystatin B and cystatin C as possible biomarkers of ovarian cancer

Objectives. To evaluate procathepsin B, as well as endogenous inhibitors of cysteine proteases (cystatin B and cystatin C) in biological fluids as possible biomarkers of ovarian cancer. To observe levels of serum procathepsin B in different age groups. Study design. The sample (N27) of women with gynaecological tumours included 18 patients with ovarian cancer (n18) and 9 patients with benign ovarian tumours (n9); 72 healthy women were in the control group. All patients were treated in Novosibirsk Regional Oncological Center, Russia. Serum samples of healthy women (n40) aged 1870 years were used as controls for common biomarker of ovarian cancer CA-125. In the Procathepsin B study, serum samples of healthy women (n32) aged 1840 years (n14), 4155 years (n10) and 5680 (n8) years were used as controls. Methods. Common biomarker of ovarian cancer, CA-125, was assayed by using a commercial kit (Vector, Koltsovo, Novosibirsk Region, Russia). Procathepsin B was measured by means of a commercial kit for human procathepsin B (R&D, USA); cystatin C was measured by commercial ELISA kits for human (BioVendor, Czechia); cystatin B was measured by ELISA kits for human (USCN Life Science Inc., Wuhan, China). Statistical analysis was performed by one-way ANOVA (Statistica 10 Program). Results. In the control group, serum procathepsin B concentration did not reveal age dependency. In th