Can Patients with HER2-Low Breast Cancer Benefit from Anti-HER2 Therapies? A Review

Abstract

Breast cancer (BC) poses a severe threat to the health of women worldwide. Currently, different therapeutic regimens are used for BC according to the pathological classification of HER2-positive or HER2-negative. Clinical reports of HER2-low expression indicate that the condition is HER2-negative, which was ineligible for HER2-targeted therapy. In contrast to HER2-zero tumors, however, HER2-low BC is a heterogeneous disease with unique genetic characteristics, prognoses, and different therapeutic responses. Clinical efficacy has been demonstrated by numerous potent and innovative anti-HER2 medications, particularly antibody–drug conjugates (ADCs). Certain ADCs, including T-DXd, have demonstrated good efficacy in some trials either used alone or in conjunction with other medications. To enhance outcomes in individuals with HER2-low BC, immunotherapy and other treatments are frequently combined with HER2-targeted therapy. There are also alternative strategies that target both HER2 and HER3 or other antigenic sites. We hope more individuals with HER2-low BC will benefit from more precise treatment regimens in the future. This article provides a review of existing research and clinical trials.

Integrated Molecular Characterization of HER2-Low Breast Cancer Using Next Generation Sequencing (NGS)

“…The identification of HER2-low BC has recently reached great clinical significance [34]. Usually reported as HER2-negative and classified as TNBC or luminal-like in clinical practice, HER2-low BC is a heterogeneous disease and shows distinct molecular profile and prognosis compared with tumors negative for HER2 by IHC [35].…”