ERBB2 and breast carcinoma: Likewise, analysis of samples (N = 481) from a Belgian study77 comparing CMF to high dose EC (HEC, epirubicin at 100 mg/m2) indicated a strong trend toward improved event-free survival (EFS) for those patients with HER2 overexpressing breast cancer (HR: 0.33) whereas those with HER2− breast cancer seemed to derive just as much benefit from CMF (HR:1.16).