Immunohistochemical demonstration of c-erb B-2 oncoprotein expression in female breast cancer and its prognostic significance.

The expression of c-erb B-2 oncoprotein was studied immunohistochemically in paraffin embedded biopsy specimens of 91 female breast carcinomas. The mean (+/- SD) age of the patients at diagnosis was 59.0 (+/- 13.2) years and they were prospectively followed-up for a mean of 12.4 years (range 11.5-13.3 years). The c-erb B-2 expression was analysed in relation to clinical stage, menopausal status, histological grade, tubular growth pattern, irregularity of nuclei, DNA ploidy and clinical outcome during the follow-up. Grade III tumours showed higher c-erb B-2 expression than low grade tumours and the c-erb B-2 expression than low grade tumours and the c-erb B-2 positivity was also related to the irregularity of the nuclei (p = 0.0815). Crude survival (p = 0.0635) and breast cancer survival (p = 0.072) could be predicted by c-erb B-2 expression, in that the c-erb B-2 negative tumours survived longer. The prediction of crude survival (p = 0.03), breast cancer survival (p = 0.04) and disease-free survival (p = 0.037) was more reliable in postmenopausal women. The results suggest that c-erb B-2 oncogene expression can be used as a prognostic parameter in predicting the biological behaviour of female breast cancer.