2018 ASCO Annual Meeting!
Session: Breast Cancer—Local/Regional/Adjuvant
Type: Poster Session
Time: Saturday June 2, 8:00 AM to 11:30 AM
Location: Hall A
Balancing the risks versus benefits of trastuzumab: A call to action for oncologists, cardiologists, and cardio-oncologists.
2018 ASCO Annual Meeting
Poster Board Number:
Poster Session (Board #46)
J Clin Oncol 36, 2018 (suppl; abstr 554)
Author(s): Moira Katherine Rushton, Isac Lima, Christopher Johnson, Meltem Tuna, Steven Hawken, Susan Faye Dent; University of Ottawa - Post Graduate Medical Education, Ottawa, ON, Canada; The Institute for Clinical Evaluative Sciences, uOttawa, Ottawa, ON, Canada; The Ottawa Hospital, Ottawa, ON, Canada; Ottawa Hospital Research Institute, Ottawa, ON, Canada; The Ottawa Hospital Cancer Centre, Ottawa, ON, Canada
Background: One year of adjuvant trastuzumab (T) is standard for early stage (I-III) HER2 + breast cancer (BC) patients (pts). Cardiac imaging is recommended every 3 months during treatment to monitor for cardiotoxicity (CTx) without evidence this practice improves pt care. Up to 30% of pts will experience transient, asymptomatic, drops in left ventricular ejection fraction (LVEF) on T, which may lead to early termination of T. Our objective was to evaluate the impact of routine CI on disease free (DFS) and overall survival (OS) in early stage HER2+ BC. Methods: Retrospective population-based cohort study of early stage BC pts treated with adjuvant T in Ontario, Canada, 2007–2016. Patient-level data was sourced through the Institute for Clinical Evaluative Sciences, which captures all patients in Ontario. The cohort was divided into three arms; A: 17-18 cycles T, no CTx; B: no CTx, ≤16 cycles T, stopped within 30 days of last cardiac imaging; C: developed CTx. CTx was defined as new diagnosis heart failure (HF), cardiomyopathy (CM) or pulmonary edema within 90 days of last cycle of T. Primary outcome: DFS; secondary outcomes: OS, cancer-specific, and cardiovascular mortality. Survival analysis was performed using Cox and subdistribution hazard models. Results: 4820 pts met inclusion criteria; 4018, 442 and 360 in arms A, B, and C respectively. Median cycles of T were 18, 13 and 14 in arm A, B and C. 5-year DFS was significantly worse in arms B (70.3%; 95% CI 63.5-74.7) and C (74.9%; 69.5-79.5) vs. 93.2% (92.3-94.0) arm A; HR for DFS were 2.96 (2.35-3.72) and 2.41 (1.87–3.12) respectively. 5-year OS was significantly worse in arms B (75.4%) and C (80.1%) vs. arm A (95.2%); HR for OS 3.99 (3.10–5.14) and 2.98 (2.24–3.95) respectively. All p-values were < 0.05. Conclusions: BC pts in Ontario who did not complete adjuvant T had significantly worse DFS and OS. A significant population stopped T shortly after cardiac imaging, without developing CTx, likely due to detection of asymptomatic drops in LVEF. These findings support the need to consider strategies to continue cancer therapy in pts with abnormal cardiac imaging, including concurrent optimization of cardiac function and cardiac risk factors.
1. TAILORx: Phase III trial of chemoendocrine therapy versus endocrine therapy alone in hormone receptor-positive, HER2-negative, node-negative breast cancer and an intermediate prognosis 21-gene recurrence score.