Safety of adjuvant trastuzumab (T) in elderly patients with breast cancer.

Abstract

282 Background: T is a mainstay in adjuvant therapy for HER2+ breast cancer (BC) patients (pts). Safety and efficacy of T in elderly patients are largely unknown. In HERA trial, NSABP B-31, NCCTG N9831 only 16% of pts were older than 60 years. Risk factors for T related cardiotoxicity are age (>50 y/o), hypertension, baseline LVEF (left ventricular ejection fraction <55%), previous antracycline therapy and BMI. Methods: Charts of pts >65 y/o with early HER2+ BC treated with T as adjuvant or neoadjuvant therapy at our institution were retrospectively reviewed. Primary endpoint was the evaluation of T cardiac toxicity and safety. Results: 22 elderly out of 172 pts (12%) were identified: 19 pts were treated only with surgery and adjuvant chemotherapy with concomitant or sequential T, 3 more pts also received neoadjuvant chemotherapy concomitant with T. According to Balducci’s criteria, fit, vulnerable and frail pts were 20, 2, 0 respectively. Median age was 69 y/o (range 65-76). Hormonal status was negative in 10/22 (45%). 21/22 were histologic grade 3. Median follow-up was 33 months. Baseline comorbidities were the following: hypertension (G2-3) in 17 pts, diabetes mellitus in 1, supra/infraventricular arrhythmia (G1-2) in 3 and 1 pts. Antracyclines were administered in 16 pts (liposomal-doxorubicin in 5 pts), a sequential taxane-regimen was used in 3 more pts. Neoadjuvant weekly Paclitaxel and concomitant T was used in 3 pts. Median basal LVEF was 65% (range 59-74%). 2 pts developed an asymptomatic 10% LVEF drop from baseline (left ventricular systolic dysfunction G1) during T treatment. Known cardiac risk factors were hypertension in 1 pt and previous antracycline based chemotherapy in both. They recovered within 9 months. One minor adverse event was atrial fibrillation (G2) during T treatment. Conclusions: T was well tolerated in elderly pts. More data are needed in order to understand the correlations between T related toxicity and cardiovascular risk factors. Long term safety of T treatment should verify the reversibility of cardiac T related toxicity on elderly pts.