...patients had received two cycles of neoadjuvant chemotherapy composed of DOX, methotrexate, and cisplatin...ABCG2 expression was significantly associated with tumor size (6.1 cm ± 2.7 cm vs. 3.9 cm ± 1.5 cm, p = 0.01) and the response to chemotherapy (62.4% ± 25.1% vs. 75.3% ± 18.7%, p = 0.02)...overall survival time of patients with normal ABCG2 expression was significantly longer than those of the high ABCG2 expression (38.9 ± 15.6 months vs. 28.4 ± 14.4 months, p < 0.01).