bcl-2 expression and apoptosis in primary and metastatic breast carcinomas

Objectives: To evaluate the role of bcl-2 and apoptotic index in the progre ssion from primary to metastatic breast carcinoma and their influence on pr ognosis. Methods: bcl-2 expression was examined by immunohistochemistry and apoptotic index by in situ end-labelling in 116 surgical breast carcinomas and lymph node metastases from 50 patients. Results: bcl-2 was observed in 69 cases (59.4%) of primitive carcinomas and 26 cases (65%) of metastatic breast carcinomas and there was agreement of bcl-2 expression between prima ry and metastatic sites except in 3 cases. bcl-2 expression was significant ly associated with several favourable prognostic features, such as small tu mour size (p = 0.03) and oestrogen and progesterone-receptor positivity (p < 0.01 and p < 0.001, respectively). A high apoptotic index was significant ly associated with a number of poor prognostic factors, including poorly di fferentiated carcinomas, large tumour size, high Ki67 expression and high m itotic count (p < 0.001 in all cases). The mean apoptotic index was higher in lymph node metastasis than in primary carcinomas (1.19 vs. 0.69, p < 0.0 1). A low bcl-2 expression and a high apoptotic index were significantly as sociated with short-relapse free survival rates (p = 0.02 and p < 0.01, res pectively), but only apoptotic extent provided independent prognostic infor mation by multivariate analysis. Conclusions: The evaluation of bcl-2 expre ssion and extent of apoptosis may provide useful prognostic information on breast cancer patients; however while increased apoptosis is strongly assoc iated with the progression from primary carcinomas to lymph node metastases , bcl-2 does not seem to play a significant role in this process. Copyright <(c)> 2001 S. Karger AG, Basel.