Epirubicin and paclitaxel with G-CSF support in first line metastatic breast cancer: a randomized phase II study of dose-dense and dose-escalated chemotherapy

An increased dose-intensity can be achieved by either higher dose of chemotherapy per cycle (dose-escalation) or by shortening the interval between cycles (dose-dense). This multicenter randomized phase II study assessed the efficacy and safety of two different approaches: epirubicin 110 mg/m2 combined with paclitaxel 200 mg/m2 every 21 days and epirubicin 75 mg/m2 combined with paclitaxel 175 mg/m2 every 10 days, both supported with G-CSF. Patients with advanced breast cancer and without prior palliative chemotherapy were scheduled for 6 cycles. Evaluable for response were 101 patients and for toxicity 106 patients. Grade ≥3 toxicities occurred in 39% of patients in the dose-escalated arm and in 29% of the dose-dense arm, mainly febrile neutropenia, thrombocytopenia, neurotoxicity and (asymptomatic) cardiotoxicity. The median delivered cumulative doses for epirubicin/paclitaxel were 656/1194 and 448/1045 mg/m2, treatment durations were 126 and 61 days, and delivered dose intensities were 36/67 and 51/120 mg/m2/week for the dose-escalated and dose-dense arm, respectively. Response rates were 75 and 70%, the progression-free survival 6 and 7 months, respectively. Dose-dense chemotherapy with a lower cumulative dose, a halved treatment time, but a higher dose-intensity may be as effective and safe as dose-escalated chemotherapy. The value of dose-densification over standard scheduled chemotherapy regimes yet needs to be determined.