Neoadjuvant ECS Versus ECF in Local Advanced Breast Cancer

S-1 is a newly developed novel oral dihydrouracil dehydrogenase inhibiting fluoro-pyrimidine drug consisting of i M tegafur (FT), 0.4 M 5-chloro-2, 4-dihydroxypyrimidine (gimeracil), and 1 M potassium oxonate (oteracil), with efficient antitumor activity and low gastrointestinal toxicity. Several studies have proved the safety and efficacy of single agent S-1 in metastatic breast cancer. This study is designed to further investigate and compare the efficacy and safety of Epirubicin-cyclophosphamide-S-1(ECS) vs. Epirubicin-cyclophosphamide-5-fluorouracil (ECF) as neoadjuvant chemotherapy in patients with local advanced breast cancer.