Real-world outcomes with novel targeted agents for HER2-positive metastatic breast cancer

A retrospective cohort study in Ontario found that survival of HER2-positive metastatic breast cancer patients treated with pertuzumab and trastuzumab emtansine in routine practice (median survival 43 months and 15 months, respectively) was inferior to results from pivotal clinical trials. These differences likely reflect differences in patient population and previous lines of therapy in routine clinical practice.