Cancer Therapy AdvisorDistinguishing HER2-Negative From HER2-Low Breast Cancer

In his discussion of the subject, Adam M. Brufsky, MD, PhD, FACP, of the University of Pittsburgh School of Medicine notes that about 50% of breast cancers categorized as HER2-negative exhibit low HER2 expression, and preliminary data suggest that new antibody-drug conjugates may be effective in treating tumors with low HER2 expression; clinical trials are currently underway. Trastuzumab should not be added to treatment plans for women with low HER2 expression, according to Dr. Brufsky, because it does not assist those with IHC 3+ or ISH-amplified breast cancer or those without those conditions. Finally, compared to triple-negative tumors, hormone receptor-positive (HR+)/HER2-negative cancers seem to have low HER2 expression more commonly.