Intercellular adhesion molecule expression in ductal carcinoma of the breast: correlation of immunohistochemical staining with cytologic smear pattern.

Recent studies suggest that altered expression of intercellular adhesion molecules (ICAM) in ductal carcinoma of the breast is associated with a higher incidence of metastases and decreased patient survival. In addition, the presence of significant cellular dyscohesion in cytologic smear preparations has been found to correlate with the presence of regional and distant metastases in a subset of patients. In this study, we correlate the smear pattern in preparations taken directly from surgically excised breast tumors with their immunohistochemical staining pattern, using antibodies directed against a panel of ICAM. We found excellent correlation, as all three tumors with an extremely high degree of tumor cell cohesion showed strong staining with all ICAM antibodies in the vast majority (>/=90%) of tumor cells in corresponding tissue sections. In contrast, five tumors displaying a largely dyscohesive smear pattern demonstrated decreased staining (</=70% of tumor cells) with at least one of the ICAM antibodies used. Tumors with intermediate degrees of cellular cohesion in smear preparations showed varied patterns of ICAM staining. These findings support the theory that loss of ICAM expression represents the physiologic basis for patterns observed in cytologic smears of ductal carcinoma of the breast. Copyright 2000 Wiley-Liss, Inc.