The objective of this study was to compare the effect of dose-intensified neoadjuvant chemotherapy with that of standard epirubicin plus cyclophosphamide followed by paclitaxel in combination with or without darbepoetin on survival in primary breast cancer. A total of 733 patients received either four cycles of neoadjuvant epirubicin 90 mg/m2 plus cyclophosphamide 600 mg/m2 every 3 weeks followed by four cycles of paclitaxel 175 mg/m2 every 3 weeks (EC→T), or three cycles of epirubicin 150 mg/m2 every 2 weeks followed by three cycles of paclitaxel 225 mg/m2 every 2 weeks followed by three cycles of combination chemotherapy with cyclophosphamide, methotrexate, and fluorouracil (Edd→Tdd→CMF). The patients were randomly assigned to receive darbepoetin or none. The primary objective was to demonstrate a superior disease-free survival (DFS) of Edd→Tdd→CMF compared with EC→T. Estimated 3-year DFS was 75.8% with EC→T versus 78.8% with Edd→Tdd→CMF hazard ratio (HR) 1.14; P = 0.37 and overall survival (OS) 88.4% versus 91.5% (HR 1.26; P = 0.237). Three-year DFS was 74.3% with darbepoetin versus 80.0% without (HR 1.31; P = 0.061) and OS 88.0% versus 91.8% (HR 1.33; P = 0.139). Patients with a pathologically documented complete response pathological complete response (pCR) had a significantly better DFS compared with those without achieving a pCR (estimated 3-year DFS: 89.2% versus 74.9%; HR 2.27; P = 0.001). Neoadjuvant dose-intensified chemotherapy compared with standard chemotherapy did not improve DFS, whereas the addition of darbepoetin might have detrimental effects on DFS.