DImmunocytochemical expression of E-cadherin on fine-needle aspirates frombreast carcinomas correlate with the cell dissociation pattern seen on smears

Altered E-cadherin expression has been suggested to be of prognostic signif icance in breast cancers and to correlate with tumor subtype and grade. A d ysfunctional, intercellular adhesion system may be responsible for the tumo r cell dissociation pattern seen on fine-needle aspirate cytology (FNAC). T he aim of our study was to determine E-cadherin expression on direct FNAC s mears from breast carcinomas and compare the results with the dyscohesion g rade of the tumor cells and the cytological grading. The material consisted of FNAs from 56 breast carcinomas. The degree of cellular cohesion was est imated semiquantitatively. Fall expression of E-cadherin was defined as a c omplete and strong membrane staining of virtually all tumor cells. All nond uctal cis well as 85% of the invasive ductal carcinomas revealed reduced ex pression or negativity for E-cadherin. In all, 25% of carcinomas with dysco hesion Grade I (mainly in groups) revealed full expression of E-cadherin, i n contrast to 12.5% of tumors with dyscohesion Grade 3 (mainly dispersed ce lls). Nuclear positivity was seen in 21% of the tumors (12 cases) and seven of these were G3 ductal carcinomas. In conclusion, E-cadherin expression c orrelated with the cell dissociation pattern seen on direct smears from FNA C of breast carcinomas, but is only one of several markers that modulate th is pattern. High-grade carcinomas rarely revealed full expression and had a high incidence of aberrant nuclear localization of E-cadherin. (C) 2001 Wi ley-Liss, Inc.