Cytoplasmic Expression of c-erb-B2 in Endometrial Carcinomas

Abstract

The aim of this study was to investigate theexpression of c-erb-B2 in endometrial cancer with attentionto both membranous and cytoplasmic staining, andto elucidate the significance of cytoplasmic signaling.Materials and Methods: c-erb-B2 reactivity was assessedby immunohistochemistry in 110 patients using a polyclonalantibody, and evaluated semiquantitatively accordingto the percentage of cells demonstrating membranousor diffuse cytoplasmic staining. Correlation wasmade with tumor stage, grade, myometrial invasion, histologictype, and disease outcome. Results: c-erb-B2overexpression, indicated by membranous and cytoplasmicstaining of at least 10% of the tumor cells, was foundin 47 (42.7%) cases. Cytoplasmic expression of c-erb-B2was observed more frequently than membranous (69.1vs. 5.5%). Synchronous cytoplasmic and membranoussignaling was noticed in 7.9% of cases. Interestingly, patientswith cytoplasmic c-erb-B2-positive tumors had asignificantly shorter survival (p = 0.047). Conclusions:These results indicate that c-erb-B2 is a specific markerof endometrial cancer. It is also an independent prognosticindicator of poor outcome. Cytoplasmic staining is asimportant as membranous staining, and is also a specificfinding.