Efficacy of neoadjuvant therapy with trastuzumab concurrent with anthracycline- and nonanthracycline-based regimens for HER2-positive breast cancer.

BACKGROUND: The aim of this study was to evaluate the pathologic complete response (pCR) rates and relapse-free survival (RFS) and overall survival (OS) of patients receiving neoadjuvant systemic therapy (NST) with trastuzumab in combination with an anthracycline- or nonanthracycline-based regimen.
METHODS: In this retrospective nonrandomized study, the authors reviewed records of 300 patients with HER2-positive breast cancer treated with either sequential paclitaxel and trastuzumab and FEC75 in combination with trastuzumab (PH-FECH) or docetaxel, carboplatin, and trastuzumab (TCH). The Kaplan-Meier product-limit method was used to estimate RFS and OS rates. Logistic regression models and Cox proportional hazards models were fit to determine the associations between NST, pCR, and survival.
RESULTS: There was no significant difference in the decline in cardiac ejection fraction; however, patients who received PH-FECH had fewer cardiac comorbidities at baseline (P = .002). pCR rates were 60.6% and 43.3% for patients who received PH-FECH (n = 235) and TCH (n = 65), respectively (P = .016). Patients who received PH-FECH were 1.45 times more likely to have a pCR (odds ratio [OR], 1.45; 95% confidence interval [CI], 1.06-1.98; P = .02). Three-year RFS rates were 93% and 71% (P < .001), and 3-year OS rates were 96% and 86% (P = .008) for patients who received PH-FECH and TCH, respectively. Patients who received PH-FECH had a lower risk of recurrence (hazard ratio [HR], 0.27; 95% CI, 0.12-0.60; P = .001) and death (HR, 0.37; 95% CI, 0.12-1.13; P = .08) than those treated with TCH.
CONCLUSIONS: The type of NST in HER2-positive breast cancer is predictive of pCR rate independent of disease and patient characteristics. Although TCH is active, PH-FECH shows a higher pCR rate and RFS advantage.