THE MUCIN MARKER, CASA, IN OVARIAN-CANCER

The Cancer-associated Serum Antigen (CASA) assay uses two monoclonal a ntibodies reactive with the core protein of the polymorphic epithelial mucin (MUC1) to measure levels of this molecule in serum. Detection o f this mucin using this assay is dependent on the level of glycosylati on of this complex molecule. A normal range of CASA levels has been es tablished with smoking, increasing age and chronic respiratory infecti ons increasing basal CASA levels. Because of the independent expressio n of CASA and CA125 in ovarian cancer, and because CASA is not elevate d in most patients with benign adnexal masses, CASA can be used in com bination with CA125 to facilitate the discrimination of malignant from benign ovarian disease. Post-operative pre-chemotherapeutic CASA leve ls appear to more accurately classify the status of residual disease i n ovarian cancer resulting in improved prognostic ability of CASA over CA125 at this time. The combination of CASA with CA125 in monitoring for recurrence of ovarian cancer results in detection of recurrence mo re than two months before clinical symptoms in 60% of patients. Althou gh this mucin marker appears to generally have a lower sensitivity for ovarian cancer than CA125, when used in combination with CA125 it can enhance the management of patients with this disease.