Fluctuation of the left ventricular ejection fraction in patients with HER2-positive early breast cancer treated by 12 months of adjuvant trastuzumab.

Abstract Background Cardiac toxicity with a decrease of the left ventricular ejection fraction (LVEF) is the main side effect induced by trastuzumab. This study reports the fluctuation of LVEF over the 12 months of adjuvant trastuzumab in PHARE trial (NCT00381901). Methods LVEF assessment was performed every 3 months while patients received trastuzumab and after completion of treatment over the first 2 years and then every 6 months afterwards. The fluctuations of LVEF over time were described and a logistic regression model was performed investigating associated factors to LVEF perfect recovery at baseline value. Results A total of 1631 patients who received 12 months of trastuzumab from PH…