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
The recommendations published here are expected to evolve as more data become available and experience with trastuzumab in the adjuvant setting grows.
Keywords: Early-stage breast cancer, trastuzumab, cardiotoxicity, anthracycline, adjuvant chemotherapy