Publication
Final analysis of the prospective WSG-AGO EC-Doc versus FEC phase III trial in intermediate-risk (pN1) early breast cancer: efficacy and predictive value of Ki67 expression
Journal Paper/Review - May 14, 2014
Nitz U, Weiss E, Böhmer S, Kreienberg R, du Bois A, Sattler D, Thomssen C, Kiechle M, Jänicke F, Wallwiener D, Harbeck N, Hoffmann G, Augustin D, Möbus V, Gluz O, Huober Jens, Kreipe H H, Kates R E, Hartmann A, Erber R, Moustafa Z, Scholz M, Lisboa B, Mohrmann S, Kuhn W
Units
PubMed
Doi
Citation
Type
Journal
Publication Date
Issn Electronic
Pages
Brief description/objective
BACKGROUND
Taxane-based adjuvant chemotherapy is standard in node-positive (N+) early breast cancer (BC). The magnitude of benefit in intermediate-risk N+ early BC is still unclear. WSG-AGO epiribicine and cyclophosphamide (EC)-Doc is a large trial evaluating modern taxane-based chemotherapy in patients with 1-3 positive lymph nodes (LNs) only.
PATIENTS AND METHODS
A total of 2011 BC patients (18-65 years, pN1) were entered into a randomized phase III trial comparing 4 × E90C600 q3w followed by 4 × docetaxel 100 q3w (n = 1008) with the current standard: 6 × F500E100C500 q3w (n = 828) or C600M40F600 d1, 8× q4w (n = 175). Primary end point was event-free survival (EFS); secondary end points were overall survival (OS), toxicity, translational research, and quality of life. Central tumor bank samples were evaluable in a representative collective (n = 772; 40%). Ki-67 was assessed centrally in hormone receptor-positive disease as a surrogate marker for the distinction of luminal A/B-like tumors.
RESULTS
Baseline characteristics were well balanced between study arms in both main study and central tumor bank subset. At 59-month median follow-up, superior efficacy of EC-Doc [versus FEC (a combination of 5-fluorouracil, epirubicin, and cyclophosphamide)] was seen in EFS and OS: 5-year EFS: 89.8% versus 87.3% (P = 0.038); 5-year OS: 94.5% versus 92.8% (P = 0.034); both tests one-tailed. EC-Doc caused more toxicity. In hormone receptor-positive (HR)+ disease, only high-Ki-67 tumors (≥ 20%) derived significant benefit from taxane-based therapy: hazard ratio = 0.39 (95% CI 0.18-0.82) for EC-Doc versus FEC (test for interaction; P = 0.01).
CONCLUSION
EC-Doc significantly improved EFS and OS versus FEC in intermediate-risk BC (1-3 LNs) within all subgroups as defined by local pathology. In HR+ disease, patients with luminal A-like tumors may be potentially over-treated by taxane-based chemotherapy.
CLINICAL TRIAL NUMBER
ClinicalTrials.gov, NCT02115204.