SAN ANTONIOA chemotherapy regimen that is both dose dense and dose intense significantly improved relapse-free and overall survival in a multicenter phase III trial by the German AGO Group. At the 29th San Antonio Breast Cancer Symposium (abstract 43), Volker J. Moebus, MD, of Staedtisches Klinikum, Frankfurt, presented the mature study results, which confirmed the interim analysis presented at ASCO 2004.
The trial enrolled 1,284 patients with early breast cancer and at least four positive axillary nodes. The experimental dose-dense regimen (ECT) included epirubicin 150 mg/m2, cyclophosphamide 2,500 mg/m2, and paclitaxel 225 mg/m2, all given every 2 weeks for three cycles. These patients also received G-CSF support. The conventional regimen (EC/T) included epirubicin at a dose of 90 mg/m2 plus cyclophosphamide 600 mg/m2 every 3 weeks for four cycles followed by paclitaxel 175 mg/m2 every 3 weeks for four cycles At the third and final analysis, with a median follow-up of 5.2 years, the 641 ECT patients had 182 relapses, compared with 226 for the 611 EC/T patients. This difference was highly significant, with a hazard ratio of 0.72 (P = .0016). The 5-year relapse-free survival was 70% in the dose-dense arm, compared with 62% in the conventional-dose arm (P = .00079). Overall survival rates were 82% and 77%, respectively (P = .029).
The improved patient outcomes were achieved at the cost of "substantial, though manageable" hematologic toxicity, Dr. Moebus said.