HER2 Testing and the Utility of Ki67

Clinical Pearls

• Recent ASCO-CAP guidelines lay out what is considered to be HER2 positive, negative, or equivocal.
• HER2 testing should be done in high volume, well-equipped, quality-assured pathology centers.
• The role for Ki67 as a prognostic marker is well-studied, though significant issues remain regarding its predictive utility and validity.
• These issues must be addressed before Ki67 is used routinely in clinical practice.

Sunil Verma, MD, MSEd, FRCPC, associate professor, University of Toronto, chair, Breast Medical Oncology, Sunnybrook Odette Cancer Centre, comments on HER2 testing and the utility of Ki67.