Key clinical point: Low vs no human epidermal growth factor receptor 2 (ERBB2, aka HER2) expression had no impact on survival outcomes in patients with hormone receptor-positive (HR+) metastatic breast cancer (BC) who were treated with targeted therapy (TT) plus endocrine therapy (ET).
Major finding: After a median follow-up of 17.9 months, both progression-free survival (P = .43) and overall survival (P = .41) were not significantly different between patients with low and no ERBB2 expression.
Study details: Findings are from an analysis of 1585 patients with HR+ metastatic BC treated with TT+ET from an institutional review board-approved breast cancer database, of which 572 and 1013 patients had no and low ERBB2 expression, respectively.
Disclosures: This study was supported by the National Cancer Institute and other sources. Some authors declared receiving personal fees, grants, or nonfinancial support from several sources.
Source: Mouabbi JA et al. Survival outcomes in patients with hormone receptor-positive metastatic breast cancer with low or no ERBB2 expression treated with targeted therapies plus endocrine therapy. JAMA Netw Open. 2023;6:e2313017 (May 11). doi: 10.1001/jamanetworkopen.2023.13017