Clinical Predictors Of Failure Of Granulocyte Colony Stimulating Factor (G-Csf) Prophylaxis In Patients With Breast Cancer Treated With Dose Dense Epirubicin (E), Cyclophosphomide (C) Plus Paclitaxel (T) Adjuvant Chemotherapy: Subgroup Analysis Of The Ncic Ctg Ma.21 Study (Nct00014222)

1033 Background: Administration of prophylactic GCSF is recommended for curative chemotherapy regimens with an estimated incidence of febrile neutropenia of ≥ 20% (Smith et al.,JCO 24:3187-3205, 2006). Clinical predictors of failure of prophylaxis are poorly understood. Methods: We retrospectively analyzed data pertaining to patients treated with dose dense EC-T chemotherapy (E: 120 mg/m2 IV Day 1 + C: 830 mg/m2 IV Day 1, q14days x 6 cycles followed by T: 175 mg/m2 IV q21days x 4 cycles) and primary prophylaxis with GCSF (5 µg/kg subcutaneously, days 2-13) on the NCIC CTG MA21 phase III study which compared 3 different anthracycline based chemotherapy regimens. An interim analysis has been published (Burnell et al., JCO, 2010). Results: 695 patients were randomized to the EC-T arm and received at least one dose of protocol therapy and primary GCSF prophylaxis. 139 (20.0%) patients experienced a febrile neutropenic event; of which 46 (33.1%) were hospitalized. There were no deaths secondary to febrile neut...