Cardiac toxic effects from paclitaxel with trastuzumab, presenting as grade 3 or 4 left ventricular systolic dysfunction (LVSD) or asymptomatic left ventricular ejection fraction decline (LVEF), were low in patients with node-negative, ERBB2-positive breast cancer, a new study published online ahead of print in JAMA Oncology has shown.1
Although trastuzumab is a life-saving therapy for many patients with ERBB2- (formerly human epidermal growth factor receptor 2 [HER2]) positive breast cancer, it is often associated with symptomatic and asymptomatic left ventricular ejection fraction (LVEF) decline.
Therefore, researchers sought to evaluate the cardiotoxic effects of a trastuzumab-based treatment without an anthracycline for early stage ERBB2-positive breast cancer.
Researchers analyzed data from an uncontrolled, single-group study that enrolled 406 patients with node-negative, ERBB2-positive breast cancer that was 3 cm or smaller, and baseline LVEF 50% or higher.
Patients with a micrometastasis in a lymph node were also eligible to participate. All patients received adjuvant weekly paclitaxel for 12 weeks with trastuzumab, followed by trastuzumab monotherapy at a dose of 2 mg/kg weekly or 6 mg/kg every 3 weeks. Researchers assessed participants’ LVEF at baseline, 12 weeks, 6 months, and 1 year.
RELATED: Breast Cancer Question-and-Answer Session With Charles Vogel, MD
Results showed that overall, only 0.5% (95% CI, 0.1 – 1.8) of patients developed grade 3 LVSD and 3.2% (95% CI, 1.9 – 5.4) developed significant asymptomatic LVEF decline. Researchers found that median LVEF at baseline was 65% and was 64% at 12 weeks, 6 months, and 1 year.
“Our findings suggest that LVEF monitoring during trastuzumab therapy without anthracyclines could be simplified for many individuals,” the authors concluded.
- Dang C, Guo H, Najita J, et al. Cardiac outcomes of patients receiving adjuvant weekly paclitaxel and trastuzumab for node-negative, ERBB2-positive breast cancer [published online ahead of print November 5, 2015]. JAMA Oncol. doi: 10.1001/jamaoncol.2015.3709.