Single Institution trial of anthracycline- and taxane-based chemotherapy for operable breast cancer: The ASTER study

The efficacy of anthracycline- and taxane-based chemotherapy for perioperative treatment of breast cancer (BC) has been established. No superiority of a cytotoxic regimen has been demonstrated, provided that administration of an anthracycline and a taxane is warranted. The ASTER study was designed to investigate the safety of 6 months of perioperative chemotherapy with Doxorubicin and Paclitaxel, followed by Cyclophosphamide, Methotrexate, and 5-Fluorouracil. ASTER enrolled patients with cT2-3 N0-1 or pT1-2 N1-3 BC, from November 2008 to August 2011. Treatment consisted of Doxorubicin 60 mg/sm, Paclitaxel 200 mg/sm q21 (AT) for three cycles followed by Cyclophosphamide 600 mg/sm, Methotrexate 40 mg/sm, 5-Fluorouracil 600 mg/sm d1,8 q28 (CMF) for three cycles, in either neo-adjuvant or adjuvant setting. All HER-positive patients received targeted therapy with Trastuzumab for 1 year. Disease-free and overall survival (DFS and OS, respectively) were estimated according to Kaplan-Meier method. Three hundred and thirty patients were enrolled, where 77.9% of cases were treated in an adjuvant setting; 65.5% received breast conservative surgery, 72.4% axillary dissection. 75.5% of cases presented estrogen receptor positivity, 66.7% progesterone receptor positivity; 18.5% of patients presented HER2-positive BC, 16.1% triple negative disease. Twenty-eight (8.5%) developed grade III-IV hematologic toxicity; nine patients (2.7%) developed grade III neurological toxicity. Loco-regional DFS was 99.6% at 1 year, 97.1% at 5 years, 95.9% at 7 years. Corresponding distant DFS was 98.4%, 90.2%, and 88.8%. One, 5, and 7-year OS was 99.6%, 94.9%, and 91.2%, respectively. Chemotherapy with ATx3→CMFx3 is confirmed safe and effective at 6.7 years follow-up. These results appear comparable to those reported in regulatory trials of most commonly prescribed anthracycline and taxane-based regimens.