Long‐term cardiac safety and outcomes of dose‐dense doxorubicin and cyclophosphamide followed by paclitaxel and trastuzumab with and without lapatinib in patients with early breast cancer

Abstract

The authors have previously reported 2 consecutive phase 2 trials in patients with early breast cancer that overexpresses human epidermal growth factor receptor 2 (HER2) to assess the feasibility of incorporating anti-HER2 therapies into dose-dense (dd) chemotherapy regimens. The incidence of congestive heart failure (CHF) at a median follow-up of 2 years was 1.4% and 3.2%, respectively. In trial A, patients received dd doxorubicin and cyclophosphamide (AC)→paclitaxel (T) (each given every 2 weeks) × 4 with trastuzumab (H) given × 1 year. In trial B, weekly T (weekly × 12) was substituted for ddT and lapatinib × 1 year was added. Herein, the authors report the longer-term incidence of CHF and distant disease-free survival (DDFS). From January 2005 to May 2008, 165 patients enrolled (median age, 46 years, with a median left ventricular ejection fraction of 68% [range, 52%-81%]), 17%of whom had previous hypertension. With a median follow-up of 84 months (trial A) and 57 months (trial B), 1 additional patient developed CHF. Therefore, the cumulative incidence of CHF was 1.4% (95% confidence interval [95% CI], 1.36%-7.7%) for trial A and 4.2% (95% CI, 4.2%-10.4%) for trial B. The 5-year DDFS for trials A and B was 92% (95% CI, 83%-97%) and 89% (95% CI, 81%-94%), respectively. Longer follow-up of these 2 studies has demonstrated that ddAC→TH only or with lapatinib is associated with a low risk of CHF and promising DDFS in patients with early breast cancer.