C-ERBB-2 ONCOPROTEIN DETECTED BY AUTOMATED QUANTITATIVE IMMUNOCYTOCHEMISTRY IN BREAST CARCINOMAS CORRELATES WITH PATIENTS OVERALL AND DISEASE-FREE SURVIVAL

The prognostic significance of c-erbB-2 oncoprotein overexpression det ected in tumours by immunocytochemical assays (ICAs) was investigated in 148 breast carcinomas. ICAs were performed under optimal technical conditions with frozen tissue sections and included automated immunope roxidase technique and computer-assisted analysis (densitometry) of di gitized coloured microscopic images. Results of quantitative ICAs (exp ressed in percentages of c-erbB-2-positive surfaces and mean optical d ensities) were correlated with the patients' follow-up in axillary lym ph node-positive (N+) and node-negative (N-) subgroups of patients. Pa tients' follow-up ranged from 9 months (for the first death) to 101 mo nths (for the 121 alive patients) with a 62.5 months mean overall foll ow-up. It was shown that marked c-erbB-2 immunocytochemical expression in tumours (cut-off point 35%) significantly correlated with the pati ents' poor overall survival in N+ and in N- patients (Kaplan-Meier, lo g-rank test, P = 0.045 and P = 0.015). Also, marked c-erbB-2 immunohis tochemical expression correlates with short disease-free (P = 0.005), recurrence-free (P = 0.048) and metastasis-free survival (P = 0.05) (K aplan-Meier, log-rank test) in N+, but not in N- subgroups. It is conc luded that in optimal conditions (automated and quantitative ICAs on f rozen sections) c-erbB immunohistochemical expression is a significant prognostic indicator in terms of overall and disease-free survival. T he c-erbB-2 protein prognostic significance is independent of node sta tus in terms of overall survival, but not of disease-free survival.