Background
Despite advances in surgery and combination chemotherapy, ovarian cancer is first in terms of death rates of gynaecological malignancies. More than 90% of ovarian cancers arise from surface epithelium and the serous histological subtype is the most commonly diagnosed epithelial ovarian carcinoma. Extensive seeding of the peritoneal cavity by tumour cells is often associated with ascites, particularly in advanced, high-grade serous carcinomas. Currently CA-125 is the most widely used biomarker in the evaluation and management of women with epithelial ovarian cancer. However, in approximately 15% of these patients CA-125 is not indicative of disease status or progression. Therefore, an alternative tumour marker would be useful. Osteopontin is a secreted, integrin-binding glykophosphoprotein which is overexpressed in ovarian cancer cells and thus may serve as a serum biomarker. By combining the data from blood and fluid from the proximity of the tumour we might be more likely to discover a protein biomarker secreted from the tumour rather than deriving from another part of the body.