The Clinical Importance of the Heterogeneity of HER2 neu

Abstract

We report on a patient with breast cancer in whom there were areas of the tumor that were 3+ positive and negative for HER2 neu by immunohistochemistry, adjacent to each other. Depending on the area tested the results were completely different. The clinical implications are important. We recommend retesting a large portion of the tumor in all cases of initially negative test results.

Keywords

• Trastuzumab
• Breast cancer
• Treatment
• Herceptin
• HER2 neu