EXPRESSION OF BCL-2 PROTEIN IN HUMAN PRIMARY BREAST CARCINOMAS AND ITS CORRELATION WITH MULTIFOCALITY, HISTOPATHOLOGICAL TYPES AND PROGNOSIS

The Bcl-2 gene product prevents programmed cell death (apoptosis) and possibly promotes tumour development. This protein has mainly been dem onstrated in the cytoplasm of various normal and neoplastic cells, inc luding normal mammary epithelia and breast carcinomas. The aim of this retrospective study was to correlate the immunohistochemical expressi on of Bcl-2 protein with the multi-unifocality and the histology of th e two main types of breast carcinoma. We used monoclonal antibody 124 to investigate Bcl-2 expression in paraffin sections of 62 primary bre ast carcinomas. Bcl-2 expression was associated mainly with this lobul ar carcinoma. High Bcl-2 protein positivity was found in this type, an d was statistically significant in comparison to the level of Bcl-2 in ductal, NOS carcinomas (lobular versus ductal, NOS, P < 0.0001). In t he entire group, including all histological types, Bcl-2 expression wa s higher in multifocal tumours (P = 0.005). Statistical significance ( P < 0.03) was also found within the group of ductal, NOS cases, showin g that Bcl-2 protein expression is associated with multifocality, irre spective of the histology of breast carcinomas. No definite associatio n between Bcl-2 expression and prognosis was found. Our results sugges t that Bcl-2 protein plays some role in the development of multifocali ty in breast carcinomas. (C) 1997 Published by Elsevier Science Ltd.