PO-468 The role of topoisomerase II-α (TOPO IIA) as a predictive factor for response to neoadjuvant anthracyclines based chemotherapy in locally advanced breast cancer

Introduction Topoisomerase II-α is a molecular target of anthracyclines; several studies have suggested that topoisomerase II-α expression is related to response to anthracycline treatment. The objective of this study was to evaluate if topoisomerase II-α overexpression predicts response to anthracycline treatment in locally advanced breast cancer patients. Material and methods This prospective study included 50 patients with primary non metastatic locally advanced breast cancer according to American Joint Committee For Cancer Staging(T3-4;N0-3)were treated between (January 2012 and Jaune 2012) at Clinical Oncology Department, Tanta University Hospital. Topoisomerase II-α, HER2, oestrogen receptor (ER), progesterone receptor (PR) expression and KI-67 were evaluated by immunohistochemistry in formalin-fixed, paraffin-embedded breast tumours from 50 patients presenting with locally advanced breast cancer. Results and discussions Tumours from 50 patients, 45 (90%) showed topoisomerase II-α overexpression, patients 34 (68%) for ER positive, 32 (64%) for PR positive and 10 (20%) for HER2 overexpression and 16 (32%) for high KI 67. Significant correlation between clinical and pathological response with topo IIA, HER2 and KI-67. p value (≤0.001), (0.005) and (0.015) respectively. 1-Responders: v Clinical (CR): 3 patients had co-expression of topo II and HER2, hormonal receptor negative and high KI-67. v Clinical(PR):43 patients majority of them had topo IIA overexpression. fig(9–10) 2-Non responders: 4 (8%) patients all had negative (TOPOII/HER2), low KI-67and 2 had hormonal receptor positive and another 2 had hormonal receptor negative. Conclusion Our data support a correlation between topoisomerase II-α expression in locally advanced breast cancer patients and improved clinical benefit with neoadjuvant anthracyclines based therapy.