Antibody immunity to the HER-2/neu oncogenic protein in patients with colorectal cancer

The HER-2/neu protein is overexpressed in approximately 20% of human adenoc arcinomas and is a defined tumor antigen in breast cancer. The purpose of t his study was ro evaluate the endogenous HER-2/neu specific antibody respon se in 57 patients with colorectal cancer. HER-2/neu specific antibodies, ti ter greater than or equal to 1:100, were detected in 14% (8/57) of patients with colorectal cancer compared to none of the normal control population ( 0/200). Furthermore, detection of HER-2/neu specific antibodies in the canc er population correlated significantly with HER-2/neu protein overexpressio n in the patients' tumor (p < 0.01). 46% of patients with HER-2/neu overexp ressing rumors (6/13) and 5% of HBR-2/neu negative tumors (2/44) had detect able HER-2/neu specific antibodies. The endogenous HER-2/neu antibody respo nse in these patients was predominantly IgG or IgA. Human Immunology 60, 51 0-515(1999). (C) American Society for Histocompatibility and Immunogenetics , 1999. Published by Elsevier Science Inc.