Method: Breast cancers tissues from 40 patients underwent to antracycline-based neoadiuvantchemotherapy and 267 treated with adiuvant therapy were collected into 4 Tissues microarrays, and classified according to pathological stage, ER, PR, HER-2 and TOPO2A status. The expression of topoisomerase 2A has been correlated to response to chemotherapy. Results: Our results show that TOPO2A expression is significantly higher in neoplasms with larger size, nodal metastasis, scant ER end PR receptors, and amplification of HER-2 gene (p < 0,00, T-test). Cancers in witch high level of TOPO2A has been found exhibit a better clinical response to treatment with anthracycline (p <0,0000, T-test). Therefore TOPO2A expression could be considered both as predictive and prognostic marker. Conclusion: The employment of TOPO2A as a predictive marker in clinical practice may be useful for the medical therapy of non-endocrine-responsive patients candidate to undergo treatment based on anthracycline, that is no free from adverse effects as cardiomyopathy and leukemia.