Can We Be Confident of HER2 Testing?

Immunohistochemistry testing adequately predicts negative HER2 status in primary breast cancer.

False-negative and false-positive HER2 test results can have profound effects on treatment recommendations and outcomes for patients. Numerous reports have found that false-negative results were reported in 1.1% to 11.5% of patients; in these patients the immunohistochemistry (IHC) result was negative (0/1) and the fluorescent in situ hybridization (FISH) result was positive.

To further study the rate of false-negative HER2 tests, investigators from eight Canadian centers conducted IHC and follow-up in situ hybridization (ISH) HER2 testing of patients with negative IHC results (IHC, 0/1+). Primary surgical specimens were analyzed by IHC and ISH (silver enhanced or fluorescent). False-negative results were defined as IHC 0/1+ but with ISH rat…

Reviewing Author

William J. Gradishar, MD

Disclosures

Consultant/Advisory BoardLilly; AstraZeneca; Gilead

Grant/Research SupportBreast Cancer Research Foundation

Editorial BoardsClinical Breast Cancer; Oncology; Annals of Surgery; Breast Cancer Research and Treatment

Leadership Positions in Professional SocietiesNational Comprehensive Cancer Network (Chair, Breast Cancer Panel); American Board of Internal Medicine (Medical Oncology Board)