PROLIFERATING CELL NUCLEAR ANTIGEN (PCNA) AND C-ERBB-2 ONCOPROTEIN IN BREAST-CARCINOMA WITH CORRELATIONS TO HISTOPATHOLOGICAL PARAMETERS AND PROGNOSIS

Overexpression of PCNA (more than 25% positive tumour cells) and positivity of c-erbB-2 oncoprotein were immunohistochemically demonstrated in 490 formalin-fixed and paraffin-embedded breast carcinomas. Overexpression of PCNA and c-erbB-2 correlated with large tumour size, presence of lymph node metastases, high histological grade (poor differentiation), and absence of steriod hormone receptors features indicating an aggressive phenotype. In univariate analysis overexpression of PCNA correlated with poor overall survival (p<0.05), whereas c-erbB-2 was of no prognostic significance. In multivariate analysis both PCNA and c-erbB-2 failed to be of independent prognostic significance. In order to identify women with different prognosis an index termed immunoscore, based upon the results of the immunoreactivity of both PCNA and c-erbB-2 was constructed. The immunoscore was correlated with tumour size, lymph node status, histological grade, and steroid hormone receptor status. In univariate analysis of survival data the immunoscore was a prognostic parameter of poor overall survival. In multivariate analysis the classical histopathological parameters such as tumour size, histological grade and progesterone receptor status turned out to be of independent prognostic significance. The immunoscore was associated with poor prognosis but did not reach independent statistical significance (p=0.08). Further studies including a larger number of patients must be carried out in order to determine the prognostic significance of the immunoscore in multivariate analysis.