OVEREXPRESSION OF HER2 NEU ONCOGENE IN PANCREATIC-CANCER CORRELATES WITH SHORTENED SURVIVAL/

For the purpose of determining the prognostic significance of HER2/neu oncogene in pancreatic and ampullary cancers, 21 pancreatic cancers o f ductal origin and six cancers of the ampulla of Vater were studied i mmunohistochemically using the monoclonal antibody (MAb) CB 11, specif ically reactive with HER2/neu product. Staining of the epithelium of t he normal duct and acini was negative or weakly positive. Moderately a nd strongly positive reactions indicated the overexpression of this ge ne, and were found in 10 of 21 (47.6%) pancreatic cancers of ductal or igin and in 2 of 6 (33.3%) ampullary adenocarcinomas. Overexpression o f HER2/neu was closely and inversely related to the survival of the pa tients with pancreatic cancer of ductal origin: 19.1 +/- 11.7 mo for t hose not overexpressing vs 7.3 +/- 3.8 mo for the overexpressors (p < 0.01). Among the pancreatic cancer group, 11 patients underwent cancer resection. The average survival for the 7 with nonoverexpressing canc er was 21.4 +/- 14.3 mo vs 10.5 +/- 3.6 mo for those with the overexpr essing tumor. Among those not undergoing resection, the average surviv al for the 4 with nonoverexpressing cancer was 15.0 +/- 3.8 mo as cont rasted to 5.2 +/- 2.1 mo for the overexpressors (p < 0.01). Although t he number of patients is small, these findings suggest that the overex pression of HER2/neu gene product may be frequently found in pancreati c cancer of ductal origin and may be one of the useful prognostic biom arkers for this cancer.