| IntroductionAt present, breast cancer is one of the mainly malignant tumors of female. It is not only a local disease, but also a disease of whole human body. The therapy principle has changed from local treatment to local treatment combining with system treatment. Preoperative chemotherapy is also called neoadjuvant chemotherapy. Recently it has been used in the treatment of breast cancer and has gained satisfied effect in the treatment of local advanced breast cancer.There is relationship between abnormal regulation of cell apoptosis and the occurrence and progress of tumor. Chemotherapy, radiotherapy and endocrine therapy all can induce the apoptosis of tumor cell, bcl-2 can block the occurrence of apoptosis, which is induced by any stimulation, and result in promoting cell survival. Ki-67 is a kind of cellular nuclear antigen and exist in G1 ana-phase and S,G2,M phase, but not in quiescent G0 phase. Ki-67 is one of the wide - used labels of cell proliferation and is utilized in assessing the proliferate ability of tumor cell. This study was designed to observe Ki-67, bcl-2 and cellular apoptosis marker AI ( apoptosis index) in breast cancer samples which have accepted neoadjuvant chemotherapy with CEF regimen, to determine the relation between the changes of expression rate of these markers of pre - and post-chemotherapy and clinical effect , and to explore the predictive value of them for chemotherapy sensitivity.Materials and MethodsSixty-six patients with primary breast cancer were collected from 2002.1 to 2003.6 in the Liaoning Cancer Hospital. They were all women. The mean age was 49.8 years old. They have received CEF chemotherapy (CTX:600mg/m2,iv;EPi:60mg/m2,iv;FuDR:500mg/m ,ivdrop every 3 weeks) for 3 cycles before operation. Clinical effect was evaluated according to UICC standard and they are CR, PR, SD and PD. Overall response rate (OR) is equal to CR plus PR, whereas no response rate is equal to SD plus PD. There are total forty - two pairs of biopsies with sufficient tissue for the accurate measurement of AI, bcl-2 and Ki-67 expression. AI was measured by using the terminal deoxynucleotidylttransferase - mediated nick end - labeling assay, while Ki-67 and bcl-2 were e-valuated by immunohistochemistry analysis. Statistical Analyses use x2 test of SPSS 10.0 software to test the difference between group.Result1. Relationship between clinical characteristic and the effect of CEF chemotherapy : Patients' age, menopausal status, tumor sizes, clinical lymph node involvement and ER are not found to be a significant predictor of chemotherapy response.2. Relationship between Ki-67, bcl-2 and AI expression before chemotherapy and the of neoadjuvant chemotherapy: Patients with Ki-67 high expression (P <0.05) are more likely to respond to treatment. The same result cannot be found in AI and bcl-2 expression ( P >0.05 ).3. The variety of Ki-67, bcl-2 and AI expression by CEF neoadjuvant chemotherapy: statistical analysis shows that the expression of Ki-67 and the value of AI are significantly decreased after neoadjuvant chemotherapy in this study ( P < 0.05 ) , but the expression of bcl-2 is increased ( P < 0.05 ).4. Relationship between the variety of Ki-67, bcl-2 and AI expression and CEF chemotherapy response: Statistical analysis shows that in PR cases, the changes of these three biomarkers are significant ( P < 0.05 ).DiscussionThe occurrence, progression and degeneration of tumor cells are closely relates to the balance between cell apoptosis and proliferation. The balance stillexists after chemotherapy and it participates in keeping the stability of tissues and cells. Before neoadjuvant chemotherapy, because of the low expression of bcl-2, the proliferation of tumor cells promotes the proliferation of cell correspondingly. bcl-2 is an important apoptosis suppression gene and its expression can prolong the life span of tumor cells, which induces tumor cells growth slowly. Whereas following with the increase expression of bcl-2 and the slow proliferat...
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