E-cadherin immunodetection was performed on frozen sections, using an immunoperoxidase procedure and with computerassisted analysis of digitized colored microscopic images in a series of 179 breast carcinomas. Quantitative immunocytochemical assays were correlated with follow-up (129 months). The results showed that reduced E-cadherin immunocytochemical expression in tumors (cut point, 4%) significantly correlated with shorter overall survival in node-negative patients (Kaplan Meier log rank test). But E-cadherin immunostained expression (cut point, 4%) did not correlate with metastasis-free or recurrence-free survival. In multivariate analysis (Cox proportional hazards regression model), E-cadherin prognostic significance for overall survival in node-negative patients was independent of the tumor size, grade, and histologic type. The results suggest that reduced E-cadherin expression detected in optimum technical conditions (frozen samples and quantitative immunohistochemistry) is an independent indicator of poor survival in node-negative patients and may be clinically relevant for the treatment of patients with breast carcinomas.