Trastuzumab-related cardiotoxicity in patients with non-limiting cardiac comorbidity.

Abstract

e12043 Background: Significant and symptomatic cardiac comorbidity (CC) is a contraindication to adjuvant trastuzumab (T) in breast cancer patients (pts). However, some pts with asymptomatic, non-limiting CC and normal baseline left ventricular ejection fraction (LVEF) receive T in the clinical practice. We sought to describe the tolerability of T in these pts. Methods: Retrospective analysis of pts with baseline asymptomatic non-limiting CC receiving adjuvant T with chemotherapy (CT) at 6 Institutions between Jul 2006 and Jan 2016. Results: Thirty-seven patients HER2-positive, operable BC at high risk of relapse BC were studied. Median age was 64y (range 36-82, 80% post-menopausal), median baseline LVEF was 61% (range 50-85%) and median BMI 26 (18-42, obesity 22%). Thirteen patients (35%) received T with adjuvant anthracycline and taxane-based, 19 (51%) taxane-based and 3 (8%) other adjuvant CT regimens (13 pts sequential, 22 pts concomitant with CT) and 2 (5%) with endocrine therapy. Prior non-limiting CC was ischemic heart disease (35%), valvular disease (30%), atrial fibrillation (19%), conduction disorders (13%), aortic aneurism (3%), and other (19%). Nine (29%) pts experienced TRC: congestive heart failure (1 pt, 3%), LVEF reduction (6 pts, 16%) and rhythm disturbances (1 pt, 3%). TRC occurred in pts with ongoing multiple cardiovascular risk factors (i.e. obesity and hypertension). Seven pts discontinued T because of TRC (19%), 5 permanently (14%) and 2 temporarily (5%). These latter pts, were able to resume and complete T after TRC resolution. At the end of adjuvant treatment, all pts showed LVEF within normal limits, except one of those who experienced a TRC (last FU value 46 %). Conclusions: This is the first analysis of TRC in pts receiving adjuvant T in the presence prior non-limiting CC. Despite the small size, our analysis shows that T is feasible in these pts and most of the TRC events were reversible at T withdrawal. Caution is needed in pts with significant ongoing cardiovascular risk factors, but when adjuvant T is deemed beneficial on breast cancer outcomes, non-limiting CC should not preclude treatment.