HE4: another 'player' in the epithelial tumor marker arena?

Three decades have elapsed since Robert Bast, working in the Gynecologic Research laboratory of Robert Knapp at Harvard, developed an antibody directed to an antigen in ovarian cancer cells, leading to the seminal publication on cancer antigen 125 (CA 125) for the monitoring of patients with ovarian cancer.[1] In the ensuing years, measuring serum CA 125 had a central role in the management of this and other gynecologic cancers of epithelial origin. Its usefulness and limitations were further defined, and many efforts to improve on its role in screening, diagnostic accuracy, and patient surveillance have been made. In addition, the eventual cloning of this MUC16 surface glycoprotein has allowed the development of, and phase III trials of, CA 125–based therapeutic vaccines.[2] Finally, we have now witnessed the successful emergence of another epithelial marker, HE4, with Bast’s group summarizing its salient features in this timely and definitive review.