Is there any cumulative dose for trastuzumab?

Trastuzumab is one of the most important agents that target human epidermal growth factor receptor 2, but its cardiotoxic effect limits to use it. The mechanism of cardiac dysfunction-related trastuzumab is still unclear. In literature, there is no definite information about the cumulative dose of trastuzumab for cardiotoxicity. In presented case, we reported a breast cancer patient who has been receiving long-term trastuzumab. We have not found any cardiac problems for duration of over four years. According to our case and literature review, we may say that trastuzumab is safely used with periodically echocardiographic control in patients with breast cancer.