Review of testing and use of adjuvant trastuzumab across a cancer network--are we treating the right patients?

This review of practice assessed all early breast cancer patients diagnosed over 12 months to determine the frequency of human epidermal growth factor receptor 2 (HER2) positivity and trastuzumab use. The frequency of HER2 positivity in routine practice (185/1319; 14%) was less than expected. A significant proportion of patients (56/185; 30%) did not receive trastuzumab, largely due to concerns about chemotherapy tolerability.