Key clinical point: Human epidermal growth factor receptor 2-low (ERBB2-low) breast cancer (BC) did not have a prognosis noticeably different from ERBB2-negative BC, thereby contradicting its classification as a unique disease entity.
Major finding: ERBB2-low vs ERBB2-negative BC was associated with slightly higher improvements in overall survival (adjusted hazard ratio [aHR] 0.98; 95% CI 0.97-0.99), especially for stage III (aHR 0.92; 95% CI 0.89-0.96) and stage IV (aHR 0.91; 95% CI 0.87-0.96) triple-negative BC, and a marginally lower likelihood of achieving pathological complete response (adjusted odds ratio 0.89; 95% CI 0.86-0.92).
Study details: Findings are from a retrospective cohort study including 1,136,016 patients with invasive BC that was not ERBB2 positive.
Disclosures: This study was supported by the Breast Cancer Research Foundation, New York, and other sources. Some authors declared receiving grants, personal fees, or research funding from several sources.
Source: Peiffer DS et al. Clinicopathologic characteristics and prognosis of ERBB2-low breast cancer among patients in the National Cancer Database. JAMA Oncol. 2023;e227476 (Feb 23). Doi: 10.1001/jamaoncol.2022.7476