- The prognosis of human epidermal growth factor receptor 2 (HER2)-positive breast cancer has been markedly improved with the addition of adjuvant HER2-targeted therapies, most notably trastuzumab.
- Neratinib, an irreversible tyrosine kinase inhibitor of HER1, HER2, and HER4, is approved for extended adjuvant treatment in patients with early-stage HER2-positive breast cancer following 1 year of trastuzumab, based on the results of the ExteNET trial. In that trial, benefit was limited to patients with hormone receptor–positive disease in subset analysis.
- Neratinib should be administered with antidiarrheal prophylaxis using loperamide, and colestipol can be considered as an adjunct.
- Tumor markers can change after neoadjuvant therapy in a small but potentially meaningful number of cases, underscoring the need to tailor adjuvant therapy to an individual patient.