Humoral immune responses of cancer patients against "Cancer-Testis" antigen NY-ESO-1: Correlation with clinical events

Humoral immune responses against the "Cancer-Testis" (CT) antigen NY-ESO-1 are frequently observed in patients with NY-ESO-1 expressing tumors. This i s in contrast to other known tumor antigens (TA) defined by antibody or cyt otoxic T cell (CTL) reactivity, i.e., MAGE-1, MAGE-3, SSX2, Melan A, and ty rosinase. No NY-ESO-1 antibody has been detected in healthy controls and pa tients with NY-ESO-1 negative tumors. In this study, we have assessed the N Y-ESO-1 serum antibody response in patients with NY-ESO-1 positive tumors o f different histological types and stages using Western blotting and an ELI SA. Of the 12 patients analyzed, 10 had demonstrable NY-ESO-1 antibodies at the start of the study. All patients were followed for changes in NY-ESO-1 antibody titers during the course of tumor treatment and clinical evolutio n. In 4 patients, an increase of NY-ESO-1 antibody titer was observed with progression of disease or extensive tumor necrosis under treatment. One pat ient showed a stable NY-ESO-1 antibody titer over 3 years along with gradua l regression of a large tumor mass. In 5 patients, a decrease of NY-ESO-1 a ntibody was detected: in 1 patient after curative tumor resection, in 3 pat ients with partial regression of metastatic disease under chemo- and immuno therapy, and in another patient with a NY-ESO-1 negative tumor relapse. Our results indicate that the induction and maintenance of NY-ESO-1 antibody i s dependent on the presence of NY-ESO-1 expressing tumors. Furthermore, cha nges in NY-ESO-1 antibody titers correlate with the evolution of NY-ESO-1 p ositive disease. Int. J. Cancer (Pred. Oncol.) 84:506-510, 1999. (C) 1999 W iley-Liss, Inc.