The correlation of c-erbB-2 oncoprotein and established prognostic factors in human breast cancer.

Background. The c-erbB-2 (HER2/neu) receptor is a transmembrane phosphoglycoprotein associated with multiple signal transduction pathways. Its overexpression in breast cancer tissue has been correlated with poor prognosis. We report preliminary data of an ongoing study in invasive breast cancer patients exploring c-erbB-2 protein overexpression in relation to established tumor characteristics of prognostic value. Materials and Methods. In primary breast carcinoma samples from 115 women undergoing surgery in our department in 1999, a polyclonal rabbit antibody to human c-erbB-2 oncoprotein was used for immunohistochemical assessment of the c-erbB-2 expression in formalin-fixed paraffin-embedded material. The data were statistically correlated with classical histopathological parameters. Results. In the studied collective of mainly postmenopausal women (75%) with a high rate of early stage breast cancer (88% pT1+2), there was no significant relation between c-erbB-2 overexpression, classified as positive in 42% of the samples, and lymph node involvement, tumor size and grade, or hormone receptor status. Conclusion. Using the presented highly sensitive method, no association between c-erbB-2 expression and established prognostic factors was found. These data are in line with reports that the value of HER2/neu determination is not fully clarified for the preadjuvant evaluation of newly diagnosed breast cancer patients.