The balance between extracellular cathepsins and cystatin C is of importance for ovarian cancer.

Background: A major step in cancer formation involves the degradation of the extracellular matrix, mediated by multiple degradative actions of (lysosomal) proteases. Extracellular release of lysosomal proteases (cathepsins) and their inhibitors has been associated with the development and progression of several types of cancer. We investigated whether cathepsins in ovarian cyst fluid (oCF) were associated with disease outcome in patients with epithelial ovarian cancer (EOC).