Clinical, Epidemiologic, and Pathologic Significance of ERBB2-Low Expression in Breast Cancer.

Importance: It is unclear whether breast cancer (BC) with low ERBB2 expression (ERBB2-low) is a distinct clinical, pathological, and epidemiological entity from BC classified as no ERBB2 expression (ERBB2-negative). Objective: To evaluate the clinical, pathological, and epidemiologic features of BC with ERBB2-low expression compared with ERBB2-negative BC in a large population study. Design, Setting, and Participants: This cohort study was conducted as part of the Pathways Study, a prospective, racially and ethnically diverse cohort study of women with BC enrolled between 2006 and 2013 in Kaiser Permanente Northern California (KPNC). The hematoxylin and eosin slides underwent centralized pathology review, including the percentage of tumor infiltrating lymphocytes (TILs). Breast biomarker results were extracted from pathology reports, and women were included if they had a documented ERBB2 value that was not classified ERBB2-positive. Data were analyzed from February 2023 through January 2024. Exposure: Clinical and tumor characteristics associated with BC and ERBB2-low or ERBB2-negative status. Main Outcome and Measures: ERBB2-low was defined as immunohistochemistry score of 1+ or 2+ (negative by in situ hybridization); ERBB2-negative was defined as immunohistochemistry score of 0+. Other data were collected by self-report or extraction from electronic health records, including BC risk factors, tumor characteristics, treatment modality, and survival outcomes, with recurrence-free survival (RFS) as the primary outcome and overall survival (OS) and BC-specific mortality (BCSM) as secondary outcomes. The clinical, pathological, and epidemiological variables were compared between ERBB2-low and ERBB2-negative BC. Results: Of 2200 eligible patients (all female; with mean [SD] age, 60.4 [11.9] years), 1295 (57.2%) had tumors that were ERBB2-low. Hormone receptors were positive in 1956 patients (88.9%). The sample included 291 Asian patients (13.2%), 166 Black patients (7.5%), 253 Hispanic patients (11.5%), 1439 White patients (65.4%), and 51 patients (2.3%) who identified as other race or ethnicity (eg, American Indian or Alaska Native and Pacific Islander). Within the hormone receptor-negative group, patients whose tumors had ERBB2-low staining, compared with those with ERBB2-negative tumors, had better OS (hazard ratio [HR], 0.54; 95% CI, 0.33-0.91; P = .02), RFS (HR, 0.53; 95% CI, 0.30-0.95; P = .03), and BCSM (HR, 0.43; 95% CI, 0.22-0.84; P = .01). In multivariable survival analysis stratified by hormone receptor status and adjusted for key covariates, patients with ERBB2-low and hormone receptor-negative tumors had lower overall mortality (HR, 0.48; 95% CI, 0.27-0.83; P = .009), RFS (HR, 0.45; 95% CI, 0.24-0.86; P = .02), and BCSM (subdistribution HR, 0.21; 95% CI, 0.10-0.46; P < .001) compared with patients with ERBB2-negative and hormone receptor-negative tumors. Within the hormone receptor-negative subtype, patients with ERBB2-low and high TILs tumors had better survival across all 3 outcomes compared with patients with ERBB2-negative and low TILs tumors. Additionally, patients with ERBB2-low and low TILs tumors had better BCSM (subdistribution HR, 0.36; 95% CI, 0.14-0.92; P = .03). Conclusions and Relevance: These findings suggest that there were clinical, pathological, and epidemiological differences between ERBB2-low and ERBB2-negative BC, raising the possibility that ERBB2-low might be a unique biologic entity.

Do knowledge about sodium, health status by self-report, and having hypertension predict sodium consumption behaviors among Southern California hospital employees?

Little is known about factors that shape sodium consumption behaviors among hospital employees targeted by recent federally funded, sodium-related policy, systems, and environmental change interventions. To address this gap in health promotion practice, we assessed the influence of sodium-related knowledge and attitudes, and health status by self-report on the sodium consumption behaviors of hospital employees targeted by the Los Angeles County Sodium Reduction Initiative. Cross-sectional surveys were administered to 1,213 hospital employees at four Southern California hospitals between 2016 and 2018. Logistic regression models examined the associations between five key sodium consumption behaviors and independent variables of interest (i.e., knowledge and attitudes about sodium, self-reported general health status, and self-reported lifetime hypertension diagnosis), controlling for covariates (i.e., sociodemographic characteristics, body mass index, the type of hospital from which participants were recruited, and the median household income in the hospital's zip code). 1,213 hospital employees completed the survey (completion rate = 50%). The belief that salt intake is harmful was associated with four of five sodium consumption behaviors, while adequate sodium intake knowledge and self-reported "good health" were associated with three of the behaviors. Hypertension diagnosis was associated with only one. Understanding sodium consumption behaviors among healthcare workers can help hospitals improve their employees' health through the promotion of healthier food environments in the workplace and changes in institutional practices.

A major problem in the United States is the overconsumption of high sodium foods. These foods often put people at higher risk of hypertension, heart disease, and stroke. Recent public health efforts have tackled this problem by making it easier to select/purchase healthier, lower sodium foods in different settings. Hospital employees are one such group that has been the focus of these interventions. Presently, little is known about what explains sodium-related dietary behaviors among hospital employees. To address this gap, we used data from a survey of hospital staff who were exposed to sodium reduction interventions in the workplace to examine how their knowledge, attitudes, and self-reported health status affected their sodium consumption. A key finding was being in "good health" and having the belief that salt intake matters for health predicted decreased sodium consumption among the survey participants. These and other study findings provide context and insights into ways in which further sodium reduction could be achieved among at-risk hospital employees.