Is it possible to increase pCR in the neoadjuvant treatment with a dose-dense/sequential combination?: results from a phase II Trial combining epirubicin and cyclophosphamide followed by paclitaxel and gemcitabine ± trastuzumab in stage II and III breast cancer patients.

PURPOSE: To evaluate the pathologic complete response (pCR) rate of a combination of epirubicin (E) and cyclophosphamide (C) followed by paclitaxel (P) and gemcitabine (G) (+ trastuzumab[T]) in Her2+ patients) in a sequential and dose-dense schedule as neoadjuvant chemotherapy for stages II and III patients with breast cancer. Secondary endpoints: clinical response rate, disease free survival, safety and correlation between pCR and biologic markers.

PATIENTS AND METHODS: Eligible patients were treated with E (90 mg/m²) and C (600 mg/m²) for 3 cycles (first sequence) followed by P (150 mg/m²) and G (2500 mg/m²) (second sequence) for 6 cycles. All drugs were administered on day 1, every 2 weeks, with prophylactic growth factor support. Weekly T (2 mg/kg [4 mg/kg first infusion]) was administered concomitantly with P and G in Her2+ patients. A core biopsy was performed before treatment for biologic markers assessment. Patients underwent surgery, radiotherapy, and adjuvant hormonal therapy according to institutional practice.

RESULTS: Seventy-three patients were treated. A pCR was achieved in 27 (37%) patients (32.1%, Her2- and 50%, Her2+). pCR was significantly higher in tumors that were hormonal receptor negative, poorly differentiated and positive for Ki67 and p53. Breast-conserving surgery was performed in 47 patients (64.4%). Most frequent grade 3/4 hematologic and nonhematological toxicities included neutropenia (12%), nausea/vomiting (17%), and transient liver enzymes elevation (7%). One patient suffered an asymptomatic and reversible decrease in left ventricular ejection fraction.

CONCLUSIONS: These results show a highly effective regimen in terms of pCR with a good toxicity profile in the neoadjuvant treatment of patients with breast cancer. The addition of trastuzumab increased pCR rate in Her2+ tumors.