The relationship between time to initiation of adjuvant chemotherapy ( TTC ) , calculated in weeks , and disease-free ( DFS ) or overall survival ( OS ) , was assessed in 921 EBC patients with rapidly proliferating tumours ( thymidine labelling index > 3 % or G3 or Ki67 > 20 % ) , randomised in a phase III clinical trial ( NCT01031030 ) to receive chemotherapy with or without anthracyclines ( epirubicincyclophosphamide , methotrexate and fluorouracil ( CMF ) versus CMFepirubicin versus CMF ) .