Inhibition of apoptosis in human breast cancer as related to prognosis

Breast tumorigenesis proceeds through an accumulation of specific genetic alterations. Breast malignant transformation is dependent on not only the rate of cell production but also on apoptosis, a genetically programmed process of autonomous cell death. It may also be important in the overall growth dynamics of neoplastic cells, both in the natural history and when they are exposed to chemotherapy or radiation. This study evaluated the biological and clinical implications of spontaneous apoptosis in human breast cancer. Apoptosis was measured in 8 normal breast tissues and 91 human breast cancer samples by Apoptag end labeling method. We found there was a significant inhibition of spontaneous apoptosis in breast cancer cells compared with normal breast epithelium. In 91 breast cancer samples, apoptotic index (AI) was strongly associated with lymph node metastasis; Low apoptosis of tumor cells was more frequent in poorly differentiated tumors and has a poor outcome.