Trastuzumab has been shown to be an effective
therapy for women with
breast cancer that overexpresses the
human epidermal growth factor receptor 2 (her2)
protein. In the pivotal metastatic
breast cancer trials, cardiac dysfunction was observed in women treated with
trastuzumab and
chemotherapy. The incidence and severity of cardiac dysfunction was greatest among patients who received
trastuzumab in combination with
anthracycline-based
therapy. Those findings influenced the design of subsequent
trastuzumab trials to include prospective evaluations of cardiac effects and protocols for cardiac monitoring and management. The risk of
cardiotoxicity has also driven efforts to develop non-
anthracycline-based regimens for women with her2-positive breast
cancers.With the increasing use of
trastuzumab, particularly in the curative adjuvant setting, the need for a rational approach to the treatment and cardiac management of the relevant patient population is clear. The mandate of the Canadian
Trastuzumab Working Group was to formulate recommendations, based on available data, for the assessment and management of cardiac complications during adjuvant
trastuzumab therapy. The panel formulated recommendations in four areas: Risk factors for
cardiotoxicity, Effects of various regimens, Monitoring, Management. The recommendations published here are expected to evolve as more data become available and experience with
trastuzumab in the adjuvant setting grows.