Five-year outcome for women randomised in a phase III trial comparing doxorubicin and cyclophosphamide with doxorubicin and docetaxel as primary medical therapy in early breast cancer: an Anglo-Celtic Cooperative Oncology Group Study

To compare the long-term outcome of women with primary or locally advanced breast cancer randomised to receive either doxorubicin and cyclophosphamide (AC) or doxorubicin and docetaxel (AD) as primary chemotherapy. Eligible patients with histologic-proven breast cancer with primary tumours ≥3 cm, inflammatory or locally advanced disease, and no evidence of distant metastases, were randomised to receive a maximum of 6 cycles of either doxorubicin (60 mg/m²) plus cyclophosphamide (600 mg/m²) i/v or doxorubicin (50 mg/m²) plus docetaxel (75 mg/m²) i/v every 3 weeks, followed by surgery on completion of chemotherapy. Clinical and pathologic responses have previously been reported. Time to relapse, site of relapse, and all-cause mortality were recorded. This updated analysis compares long-term disease-free (DFS) and overall survival (OS) using stratified log rank methods. A total of 363 patients were randomised to AC (n = 181) or AD (n = 182). A complete pathologic response was observed in 16% for AC and 12% for AD (P = 0.43). The number of patients with positive axillary nodes at surgery with AC was 61% and AD 66% (P = 0.36). At a median follow-up of 99 months there is no significant difference between the two groups for DFS (P = 0.20) and OS (P = 0.24). Deaths were due to metastatic breast cancer in 96% of patients. Our data do not support a clinical benefit for simultaneous administration of AD compared with AC. However, the data do not exclude a smaller benefit than the study was powered to detect and are consistent with an increase in both disease-free and overall survival of about 5% for AD compared with AC. Outcome is consistent with the pathologic complete response following surgery.