Gibson J, et al. - A retrospective inquiry was performed to evaluate the cardiovascular and oncologic outcomes in relation to interruption or continuation of trastuzumab (T) treatment in the context of mild left ventricular dysfunction (LVD). Findings demonstrated that pre-existing cardiovascular disease and cardiac risk factors did not appear to increase the likelihood of a T hold. Notably, T continuation did not increase the risks of adverse cardiovascular outcomes after the development of mild LVD but holding T was related to a 10% absolute risk increase in breast cancer recurrence. Furthermore, an 11% absolute risk increase in breast cancer relapse was reported when trastuzumab was transiently held, even when 17 doses of T were given. This study did not yield statistically significant results but suggests the need for a larger study to inform evidence-based guidelines on the interruption of T in the context of LVD.