Efficacy and safety of neoadjuvant trastuzumab combined with paclitaxel and epirubicin: A retrospective review of the M. D. Anderson experience

BACKGROUND. A previously published prospective randomized phase 3 trial showed that administration of 24 weeks of primary systemic chemotherapy (PST) with paclitaxel and FEC₇₅ (fluorouracil, epirubicin, cyclophosphamide) concurrently with trastuzumab in patients with HER2-positive primary breast cancer resulted in a 60% pathologic complete response rate (PCR) with no associated severe cardiac toxicity. The purpose of this study was to review the efficacy and safety of a similar regimen outside the setting of a clinical trial. METHODS. Patients with HER2-positive breast cancer (defined as either immunohistochemical 3+ or fluorescence in situ hybridization-positive) that had received 24 weeks of neoadjuvant trastuzumab concurrently with taxane and anthracycline-based chemotherapy between 2004 and 2006 were included in the analysis. PST chemotherapy consisted of paclitaxel (80 mg/m²) weekly for 12 weeks followed by 4 cycles of FEC₇₅ (500 mg/m², 75 mg/m², and 500 mg/m², respectively). RESULTS. Forty patients were identified. The median age was 48 years (range, 29-81). In all, 60% of patients had stage III disease and 4 had inflammatory breast cancer. The PCR rate was 55% (95% confidence interval [CI], 38.5%-70.7%). At a median follow-up of 19 months. 5 patients had a recurrence, of which 4 did not achieve a PCR. No severe cardiac events were observed. CONCLUSIONS. Stage II and III HER2-positive breast cancer patients achieved a high rate of PCR with trastuzumab given concurrently with paclitaxel and FEC₇₅ chemotherapy. No severe cardiac events were observed with the regimen. The data concur with the results of a previously published trial.