Matador,a multicenter clinical trial. Non-metastatic breast cancer patients were randomized between TAC or ddAC

Between 2004 and 2012, patients with pT1-3, pN0-3, M0 breast tumors were randomised between adjuvant dose-dense doxorubicin-cyclophosphamide (ddAC) versus docetaxel-doxorubicin-cyclophosphamide (TAC). Trial registration numbers: ISRCTN61893718 and BOOG 2004-04. Overall design: Total number of patients in the MATADOR study: 664. For 604 (90.9%) patients, tumor tissue was available for gene expression analysis. Library preparation failed in 7 patients. Six out of 597 sequenced samples did not meet the quality checks. 62 patients had a clinically low risk of recurrence according to the modified Adjuvant! Online and would not receive adjuvant chemotherapy according to current guidelines. In this group no events occurred. For one patient survival data was missing. The remaining 528 patients were used to develop DTS.