c-erbB-2 Oncoprotein Overexpression in Breast Cancer

Hwang, Tae Sook; Cho, Kyung Ja; Kim, Young Bae; Huh, Joo Ryung; Jang, Ja June

Abstract

c-erbB-2 oncogene is a normal cellular proto-oncogene coding transmembrane glycoprotein structurally similar to the epidermal growth factor receptor. Amplification of this oncogene in a variety of human adenocarcinomas has been reported and is particularly well documented in breast carcinoma. It has been suggested that amplification of this oncogene is indicative of poor prognosis and is valuable only second to the lymph node status. Using immunohistochemical staining for the c-erbB-2 protein, overexpression of this protein was analysed in 228 primary breast cancer specimens and the frequency of overexpression and the relationship between overexpression and the other established prognostic variables are evaluated. Ninty three cases out of 228 cases(40.8%) show postive oncoprotein overexpression and using the chi-squared test for a trend, a significant correlation was found between c-erbB-2 protein staining and the histological grade, lymph node status, and estrogen receptor status(P<0.05). No significant association was found between staining and the patient's age and tumor size. Most of the tumors with histological types known to have good prognosis showed negative expression. Above findings strongly suggest that expression of c-erbB-2 oncogene is another independent indicator of poor prognosis in breast carcinoma.