Genomic Characterization and Prognostic Significance of Human Epidermal Growth Factor Receptor 2-Low, Hormone Receptor-Positive, Early Breast Cancers From the BIG 1-98 and SOFT Clinical Trials

SJ Luen; LC Brown; CT Van Geelen; P Savas; R Kammler; P Dell'orto; O Biasi; AS Coates; RD Gelber; B Thürlimann; M Colleoni; GF Fleming; PA Francis; MM Regan; G Viale; S Loi

Journal article

Genomic Characterization and Prognostic Significance of Human Epidermal Growth Factor Receptor 2-Low, Hormone Receptor-Positive, Early Breast Cancers From the BIG 1-98 and SOFT Clinical Trials

SJ Luen, LC Brown, CT Van Geelen, P Savas, R Kammler, P Dell'orto, O Biasi, AS Coates, RD Gelber, B Thürlimann, M Colleoni, GF Fleming, PA Francis, MM Regan, G Viale, S Loi

JCO Precision Oncology | American Society of Clinical Oncology (ASCO) | Published : 2025

DOI: 10.1200/PO-24-00599

Abstract

PURPOSE To investigate whether hormone receptor-positive, human epidermal growth factor receptor 2-low (HR+HER2-low) versus HR+HER2-zero early breast cancers have distinct genomic and clinical characteristics. METHODS This study included HR+, HER2-negative early breast cancers from patients enrolled in the phase III, randomized BIG 1-98 and SOFT clinical trials that had undergone tumor genomic sequencing. Tumors were classified HR+HER2-low if they had a centrally reviewed HER2 immunohistochemistry (IHC) score of 1+ or 2+ with negative in situ hybridization and HR+HER2-zero if they had an HER2 IHC score of 0. RESULTS A total of 1,795 tumors were evaluable for this study (BIG 1-98 n = 520, SOF..

View full abstract