Increased plasma concentrations of anterior gradient 2 protein are positively associated with ovarian cancer

Ovarian cancer is often asymptomatic and is diagnosed at an advanced stage with poor survival rates, thus there is an urgent need to develop biomarkers for earlier detection of ovarian cancer. In the present study, we demonstrate for the first time that the previously reported metastasis-inducing protein AGR2 (anterior gradient protein 2) can be detected in the blood of ovarian cancer patients. Using a newly developed ELISA, we show significantly increased concentrations of AGR2 protein in plasma from cancer patients relative to normal controls. Plasma AGR2 concentrations were highest in stages II and III ovarian cancer patients and were similarly elevated in patients with both serous and non-serous tumours. The identification of elevated plasma concentrations of AGR2 may provide a useful biomarker to aid in the discrimination of normal and ovarian cancer patients particularly when used in combination with CA125.