E-CADHERIN QUANTITATIVE IMMUNOCYTOCHEMICAL ASSAYS IN BREAST CARCINOMAS

The reduction of E-cadherin expression, which is involved in the initi al step of invasion and metastasis of cancer, was investigated in 218 human breast carcinomas. Quantitative immunohistochemical assays (ICAs ) were performed on frozen sections, Quantitation was assessed by proc essing digitized microscopic images of immunoreactions using a compute rized system of image analysis (SAMBA). The results were correlated wi th clinicopathological data and quantitative immunodetection of other molecules. E-cadherin expression was significantly (P<0.001) stronger in ductal carcinomas than in lobular carcinomas and stronger (P<0.01) in low grades than in high grades, but E-cadherin was independent of l ymph node status and tumour size. Also an inverse significant (P<0.01) relationship was observed between E-cadherin expression on tissue sec tions and positive immunoreactions with anti-P53, MIB1 (growth fractio n), and anti-c-er6-B2 product. Conversely, strong positive and anti-E- cadherin immunoreactions correlated with strong positive anti-ER and a nti-PR immunoreactions (P<0.01). No relationship was observed between E-cadherin and the results of quantitative ICAs of cathepsin D, CD31, and P-glycoprotein, assessed on consecutive sections from the same fro zen tissue samples. The results show that preserved E-cadherin express ion correlates with high degree of tumour differentiation, low prolife rative activity, and low expression of prognostic markers. The deregul ation of E-cadherin is independent of other steps of tumour invasion, such as protease digestion of extracellular matrix and angiogenesis. ( C) 1997 by John Wiley & Sons, Ltd.