Survival Of Hereditary Nonpolyposis Colorecancer (Hnpcc) Patients Compared With Sporadic Colorectal Cancer Patients: A Pilot Study.

Background, The c-erbB-2 (HER-2/neu) oncogene encodes a 185 kD transmembrane protein, pl85, which displays tyrosine kinase activity, Overexpression and amplification of c-erbB-2 in human breast cancers predicts chemotherapy resistance and a poor prognosis, The frequency of c-erbB-2 up-regulation in colon cancers remains unknown, Methods, We analyzed c-erbB-2 expression in 97 human colorectal cancers (l6-Dukes A, 21-B, 24-C, 36-D) using immunohistochemistry (c-neu, Ab-3, Oncogene Science) and examined gene amplification using fluorescent in situ hybridization (FISH), Staining intensity was graded (0-3+) and examined in relation to tumor stage and histologic grade, Results, A membranous staining pattern was detected in 5 (5 %) cases and all had intense (3+) immunoreactivity, c-erbB-2 amplification was detected in all 5 of these cases, In 86 of 97 tumors, non-membranous, cytoplasmic staining was detected [23(1+), 55(2 +), 8(3 + )]; 6 cases were negative.In a random subset.cytoplasmic staining was not associated with amplification, C-erbB-2 staining was independent of tumor stage.All membranous cases had moderate differentiation; negative cases had poor and moderate differentiation.In conclusion, only tumors exhibiting membranous staining had c-erbB2 amplification.Cytoplasmic staining was frequently observed but was not associated with amplification.The clinical significance of c-erbB-2 expression and amplification in colon cancer await further study,