[Correlation between apoptotic index, bcl-2 protein expression and progression and prognosis in breast carcinoma]

Apoptosis is considered to play a critical role in tumorigenesis. It has been shown that apoptosis is controlled by both pro-oncogenes bcl-2, c-myc and tumor-suppressor genes p53. We determined the apoptotic index (AI) on light microscopy and detected immunohistochemically the expression of bcl-2 and p53 in patients with breast cancer. The correlations between AI and clinicopathological factors, bcl-2 and p53 were also analyzed. Our results showed that bcl-2 expression was down-regulated in the process from normal breast epithelial cells to intraductal carcinoma and from intraductal carcinoma to invasive carcinoma. We failed to detect p53 protein in normal breast epithelial cells, and p53 positivity was 24% and 30% in intraductal and invasive cancer tissues, respectively. Moreover, AI was significantly associated with histological grade, mitotic index, and bcl-2 and p53 expression. In univariate analyses, lower AI and bcl-2 expression was significantly predictive of a better prognosis for both disease-free survival and overall survival. These results suggest that apoptosis and apoptosis-related gene (bcl-2, p53) are related to progression and prognosis in breast cancer.