1397P - Cardiac Safety of (NEO) Adjuvant Trastuzumab in the Brazilian Community Setting: A Single Center Experience

Abstract

ABSTRACT Background Trastuzumab-associated cardiotoxicity (TAC) has been established in the context of clinical trials. However, when newly registered agents are used in a broader patient population, their safety profile does not always mirror that of the pivotal trials. Trastuzumab (T) only became available in the Brazilian public sector in 2008 and herein we report our off-trial experience so far. Methods Retrospective, single center cohort of HER-2 positive breast cancer patients (pts) treated with (neo)adjuvant chemotherapy and T from July 2008 to March 2012. 95.3% were treated according to local protocol (11.4% TCH; 83.9% AC-TH). Major cardiac event (MCE) was defined as a left ventricular ejection fraction (LVEF) drop of 10% and absolute drop to Results 237 women were identified: median age 53 y (27-83), 99.6% ECOG-PS 0-1, median body mass index 27.4 kg/m2 (17 – 46), 30.4% had hypertension (HTN), 8.8% had diabetes mellitus (DM), 5.9% had previous cardiopathy. 54.8% had ER-positive tumors; 40.7% received neoadjuvant T; most were stage II or III (22.3% and 37.1%). Median number of ECHO assessments was 2.7 (0-6); 136 pts (57.2%) completed T as planned. 20.2% had MCE (13.9% discontinued T). 3.8% discontinued T due to symptomatic HF and 5% for non-cardiac reasons. 41.6% of MCE pts recovered cardiac function. Median initial LVEF was 64.83 ± 1.5 % (no event) vs 64.81 ± 1.5 % (MCE) p = 0.26; median 3-month LFVE was 64.67 ± 4 % (no event) vs 56.12 ± 3 % (MCE) p = 0.0036. HTN, DM, obesity, age, radiotherapy, use of anthracycline and previous cardiopathy were not significantly associated with TAC. Conclusions Our results suggest that TAC in our routine practice is slightly higher than reported in literature (6 to 17%), possibly reflecting selection bias in clinical trials. Symptomatic TAC was as expected for AC-TH (4%). We failed to identify risk factors for TAC, possibly due to the low number of events. Cardiac function must be closely monitored during T treatment and careful pt selection is crucial. Disclosure All authors have declared no conflicts of interest.