BUFFALO, NY - January 22, 2025 – A new #review was #published in Oncotarget's Volume 16 on January 20, 2025, titled “Evolving concepts in HER2-low breast cancer: Genomic insights, definitions, and treatment paradigms." Researchers Whitney L. Hensing, Emily L. Podany, James J. Sears, Shaili Tapiavala, and Andrew A. Davis from the University of Missouri-KC School of Medicine and Washington University in St. Louis School of Medicine explore HER2-low breast cancer, a recently recognized type of breast cancer that is changing the way clinicians should approach treatment. The review explains what makes HER2-low breast cancer different and highlights new treatment options that are helping patients. “Breast cancer, which has been historically classified as HER2-positive versus HER2-negative, is currently facing a paradigm shift in both the definition of HER2 status and in the existing treatment algorithms.” Breast cancer is usually classified into two main types based on the HER2 protein: HER2-positive or HER2-negative. HER2-low breast cancer falls somewhere in between. Thanks to new targeted treatments, such as a drug called trastuzumab deruxtecan, patients with HER2-low breast cancer now have more options and better chances of responding to treatment. The review looks at recent studies on the genetics of HER2-low breast cancer. Researchers found that these tumors are often hormone receptor (HR)-positive, meaning they respond to hormones like estrogen. Some tumors also carry a common genetic change called a PIK3CA mutation, which could affect how well treatments work. However, experts say HER2-low breast cancer is not a completely separate breast cancer type but rather an opportunity for more personalized treatment. “Despite evidence from existing literature that HER2-low breast cancer does not represent a distinct biologic and prognostic subtype, the introduction of HER2-low expression as a therapeutic target has expanded patient eligibility for a potent class of anti-HER2 drugs, HER2-directed ADCs, with potential for significant efficacy.” Despite these advances, diagnosing HER2-low breast cancer can still be difficult. Current testing methods are not always accurate, and different laboratories may get different results. The review calls for better detection methods to make sure patients who can benefit from these new treatments are correctly identified. With cancer treatments becoming more personalized, the review also explains how clinicians can fit HER2-low treatments into existing guidelines to help patients. The success of targeted therapies is changing how breast cancer is treated, especially for patients whose cancer has metastasized. In conclusion, experts believe ongoing research will continue to improve the way HER2-low breast cancer is diagnosed and treated. However, they stress the need for better detection methods and continued exploration of new therapies to help patients get the best possible care. DOI - https://doi.org/10.18632/oncotarget.28680 Correspondence to - Andrew A. Davis - aadavis@wustl.edu About Oncotarget Oncotarget (a primarily oncology-focused, peer-reviewed, open access journal) aims to maximize research impact through insightful peer-review; eliminate borders between specialties by linking different fields of oncology, cancer research and biomedical sciences; and foster application of basic and clinical science. To learn more about Oncotarget, please visit https://www.oncotarget.com and connect with us: Facebook - https://www.facebook.com/Oncotarget/ X - https://twitter.com/oncotarget Instagram - https://www.instagram.com/oncotargetjrnl/ YouTube - https://www.youtube.com/@OncotargetJournal LinkedIn - https://www.linkedin.com/company/oncotarget Pinterest - https://www.pinterest.com/oncotarget/ Reddit - https://www.reddit.com/user/Oncotarget/ Spotify - https://open.spotify.com/show/0gRwT6BqYWJzxzmjPJwtVh MEDIA@IMPACTJOURNALS.COM