Toxicity analysis in the ADEBAR trial: Sequential anthracycline-taxane therapy compared with FEC120 for the adjuvant treatment of high-risk breast cancer

Background: Data from meta-analyses have shown taxane-containing therapies to be superior to anthracycline-based treatments for high-risk breast cancer. Patients and Methods: The ADEBAR trial was a multicenter phase III trial in which patients with lymph node-positive breast cancer were prospectively randomized for either sequential anthracycline-taxane or FEC120 therapy. Patients received 4× epirubicin (90 mg/m ²) and cyclophosphamide (600 mg/m ²) every 3 weeks (q3w), followed by 4× docetaxel (100 mg/m ²) q3w (EC-Doc arm), or 6× epirubicin (60 mg/m ²) and 5-fluorouracil (500 mg/m ²) on days 1 and 8 and cyclophosphamide (75 mg/m ²) on days 1-14, q4w (FEC arm). We compared both arms with respect to toxicity and feasibility. Results: Hematological toxicity was found significantly more often in the FEC arm. Febrile neutropenia was seen in 11.3% of patients in the FEC arm and in 8.4% of patients in the EC-Doc arm (p = 0.027). Non-hematological side effects of grade 3/4 were rarely seen in either arm. Therapy was terminated due to toxicity in 3.7% of the patients in the EC-Doc arm and in 8.0% of the patients in the FEC arm (p = 0.0009). Conclusion: The sequential anthracycline-taxane regimen is a well-tolerated and feasible alternative to FEC120 therapy.