Incidental Finding of Raised CA125: a Cause for Concern?

Abstract

Cancer antigen 125 (also known as carbohydrate antigen 125 or CA 125) is an antigen first identified by Bast et al. Although much research has been done to understand the molecular structure of CA 125, its function remains a source of much speculation. At present, CA 125 is most commonly used in the diagnosis of epithelial non-mucinous ovarian cancers, and in monitoring their response to treatment. Following surgical resection, CA 125 levels are expected to half within 10 days and it is therefore a useful tool for assessing response to treatment as well. We present a case of incidental finding of rasied CA125, followed by the literature review to discuss a better understanding of the factors that lead to CA 125 production, its mechanisms of action, and the nature and functions of its subspecies may help in improving its use as a standalone diagnostic tool.