Purpose: A single-arm phase II multicenter trial of the combination of cyclophosphamide (C), epirubicin (E), and 5-fluorouracil (F) followed by docetaxel as neoadjuvant chemotherapy is being conducted by the Japan Breast Cancer Research Group. This report describes an interim analysis of the clinical response and safety of 79 patients who finished preoperative chemotherapy and surgery. Patients and Methods: Patients with operable breast cancer received C at 500 mg/m 2, E at 100 mg/m 2, and F at 500 mg/m 2 every 21 days for 4 cycles followed by docetaxel at 75 mg/m 2 every 21 days for 4 cycles. Results: Of the 79 patients evaluable for analysis the median age was 46 years (28-59). and 61 patients (77.2%) had T2 tumors. A total of 312 of 316 (98.7%) cycles of CEF and 296 of 312 (94.9%) cycles of docetaxel were administered. Average total cumulative dose was 92% and 95% for CEF and docetaxel, respectively. The rate and grade of edema, neuropathy, arthralgia and myalgia were higher with docetaxel than with CEF. The overall clinical response rate was 70.9%. Breast conserving surgery was performed in 31 of 42 patients (73.8%) with a base-line tumor size of more than 3 cm. Conclusions: Interim data suggest that CEF followed by docetaxel is an active and tolerable neoadjuvant chemotherapy regimen. A final analysis is planned for 2005.