Clinicopathologic characteristics and prognosis of HER2-low breast cancer compared with HER2-negative breast cancer

It is not clear whether HER2-low breast cancer is a clinically distinct subtype of the disease. A retrospective cohort study using the National Cancer Database found minimal prognostic differences between HER2-low and HER2-negative breast cancer. The authors conclude that, moving forward, outcomes in HER2-low breast cancer will be driven by HER2-directed antibody-drug conjugates, rather than intrinsic differences in biological characteristics associated with low-level HER2 expression. The findings do not support the classification of HER2-low breast cancer as a unique disease entity.