HER2 testing: current status and future directions.

Accurate determination of human epidermal growth factor receptor 2 (HER2) status is critical for optimizing breast cancer outcomes. In 2007, the American Society of Clinical Oncology (ASCO) and the College of American Pathologists (CAP) developed guidelines for HER2 testing to reduce inaccuracy. However, current ASCO/CAP criteria may restrict access to HER2-targeted therapy for some patient groups who would derive a clear clinical benefit. ASCO/CAP are currently reviewing their guidelines to further optimize HER2 testing and include emerging techniques. Guidelines are critical for optimizing care, as is ongoing research into techniques that accurately and reproducibly assess HER2 status.