OBJECTIVE - This study was undertaken to determine the expression of apoptosis in breast cancer and to evaluate it's significance as a prognostic marker.
METHODS - A series of 91 invasive breast cancer was analysed for the expression of apoptosis by using the 3-end-labeling method of DNA in tissue sections. The apoptotic indexes were the percentages of apoptotic cells among tumor cells.
RESULTS - The end-labeling method allowed a precise evaluation of the expression of apoptosis. Apoptosis occurred in 91.2% of breast cancer patients, and apoptotic indexes were divided into two groups, 0-0.21 and 0.28-0.62. Low apoptotic index was related to axillary lymph node metastasis (P < 0.01). In survival analysis, higher apoptotic index was related to disease free survival (P = 0.0095) and overall survival (P = 0.0348) in the entire cohort. Cox's analysis showed apoptotic index had no independent prognostic value.
CONCLUSION - The apoptosis was a spontaneous phenomenon in breast cancer tissue, and the expression was different from each other. Further analysis was needed to clarify the relationship between apoptosis and prognosis, especially the response to adjuvent therapy.