Odai-Afotey, Ashley A

Abstract BACKGROUND: Obesity is prevalent in Hispanic patients (pts) with breast cancer (BC), but this population is often underrepresented in studies of weight loss interventions (WLIs). The BWEL trial (Alliance A011401; NCT02750826) is a phase III randomized trial testing the impact of a 2-year (yr) telephone-based WLI on invasive disease-free survival in pts with stage II-III HER2-negative BC and a body mass index (BMI) > 27 kg/m2. At 12 months (mo), Hispanic pts lost less weight than White pts on the WLI. Here, we evaluate differences in intervention engagement over the first 12 mo by language preference and ethnicity among BWEL pts on the WLI. METHODS: BWEL randomized pts 1:1 to WLI + health education (HE) or HE alone. WLI +HE pts received semi-structured telephone-based health coaching in English or Spanish, in addition to access to an activity monitor, wireless scale and meal replacement shakes. Pts self-reported ethnicity and their preferred language for the WLI. Kruskal Wallis and chi-square tests were used to assess language and ethnicity differences in demographic and treatment factors for continuous and categorical variables, respectively. Percent weight change and mean values for intervention attrition, number of calls, call duration, number of shake shipments, and frequency of activity monitor use and weight tracking over 12 mo were compared between Spanish-preferred Hispanic pts (SH), English-preferred Hispanic (EH) pts and non-Hispanic (NH) pts using ANOVA. Pts with missing language, ethnicity or 12 mo weight data were excluded from analysis. RESULTS: 1591 pts were randomized to the WLI + HE from 08/2018 to 02/2021. 80.5% of pts were White, 12.8% Black and 7.1% Hispanic. 1190 pts had 12 mo weight and language available. Among the 87 WLI + HE pts who had available data and identified as Hispanic, 34% were SH and 66% EH. SH WLI pts were younger (in yrs: 49.5 SH, 51.1 EH, 53.9 NH, p=0.006) and had lower BMI (32.2 SH, 35.1 EH, 34.5 NH, p=0.007). At 12 mo, SH WLI pts lost 2.4% of baseline body weight vs 3.3% in EH and 5.1% in NH (p=0.051) (Table). Compared with EH and NH WLI pts, SH WLI pts participated in fewer calls (15.7 SH, 21.1 EH, 24.3 NH, p< 0.0001), had fewer days of activity monitor use (134.2 SH, 177.3 EH, 205.3 NH, p=0.015) and fewer days of weight tracking (65.3 SH, 96.8 EH, 148.2 NH, p<0.0001), but had more shake shipments (3.9 SH, 3.5 EH, 3.0 NH, p=0.015). There were no significant differences in attrition rate or call duration by language preference or ethnicity. CONCLUSIONS: In a large phase III WLI study in breast cancer patients, engagement with the WLI appeared lower in SH pts, despite provision of the intervention in Spanish. More work is needed to improve accessibility and efficacy of WLI studies among non-English speaking populations. Support: U10CA180821, U10CA180882, UG1CA189823; https://acknowledgments.alliancefound.org. Citation Format: A. Odai-Afotey, K. V. Ballman, L. M. McCall, C. Cao, C. Alfano, V. Bernstein, T. E. Crane, L. M. Delahanty, L. Frank, P. J. Goodwin, O. Hahn, D. L. Hershman, J. O. Hopkins, M. Irwin, E. L. Mayer, L. Minasian, L. Nebeling, M. Neuhouser, E. D. Paskett, P. A. Spears, V. Stearns, C. A. Thomson, T. A. Wadden, A. Weiss, J. White, C. Hudis, E. P. Winer, L. Carey, A. H. Partridge, J. Ligibel. Variation in weight loss and intervention engagement in the Breast Cancer Weight Loss (BWEL) trial by language and ethnicity (Alliance) [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS4-09-29.

1586 Background: Black and Hispanic breast cancer (BC) survivors have a higher prevalence of obesity and experience less success with weight loss interventions (WLI) than White BC survivors. The BWEL trial (Alliance A011401; NCT02750826) is a phase III randomized trial evaluating the impact of a 2-year telephone-based WLI on invasive disease-free survival in participants (pts) with stage II-III HER2-negative BC and a BMI ≥ 27 kg/m 2 . At 12-months, the WLI induced significant weight loss across demographic factors, including race and ethnicity. However, Black and Hispanic pts lost less weight and completed fewer calls than White pts. Here, we evaluate intervention adherence, engagement and tool utilization in BWEL pts by race and ethnicity. Methods: BWEL randomized pts to a WLI plus health education (HE) or HE alone. WLI pts received semi-structured telephone-based health coaching, delivered in English or Spanish, and received an activity monitor and wireless scale. Pts self-reported race and ethnicity. Mean values for call duration, call density (time to complete the initial 12-week intensive intervention phase), intervention attrition, and frequency of Fitbit use and weight tracking over 12-months were compared by race and ethnicity, comparing least squares means with Tukey-Kramer adjustment for multiple comparisons with adjusted p-values. Results: Of 3181 pts randomized to the study between 08/2016 and 02/2021, 1591 pts were allocated to the WLI arm. 80.5% of pts were White, 12.8% Black, and 7.1% Hispanic. Average BMI was 34.5 (±5.7) kg/m2. Compared to White pts, Black pts had fewer days of Fitbit usage (113.6 vs. 159.8, p<0.0001) and weight tracking (77.9 vs. 135.6 days, p< 0.0001). Hispanic pts had fewer days of Fitbit usage (108.8 vs. 154.9, p= 0.001) and weight tracking (87 vs. 129.5 days, p=0.0002) compared to non-Hispanic pts. There were no differences in attrition rate, average call duration, or call density by race or ethnicity. Conclusions: In a phase III WLI trial, engagement with tools designed to support weight loss was significantly lower in Black and Hispanic pts. Future work is needed to explore ways to enhance engagement and improve weight loss outcomes for racial and ethnic minority pts. Support: U10CA180821, U10CA180882, UG1CA189823; https://acknowledgments.alliancefound.org . Clinical trial information: NCT02750826 . Measure of engagement Race Ethnicity WhiteN=1281 BlackN=204 p-value Non-HispanicN=1459 HispanicN=113 p-value Withdrew from intervention n (%) 58 (4.5%) 13 (6.4%) 0.56 70 (4.8%) 6 (5.3%) 0.51 Call Duration (min)Mean (SD) 34.5 (7.6) 34.6 (9.1) 0.99 34.6 (7.8) 33.3 (7.9) 0.25 Call density(weeks)Mean (SD) 14.2 (7.2) 14.2 (8.8) 0.99 14.2 (7.3) 14.2 (9.7) 0.99 Days of Fitbit UseMean (SD) 159.8 (132.2) 113.6 (124.7) < 0.0001 154.9 (131.8) 108.8 (125.7) 0.001 Days of weight trackingMean (SD) 135.6 (109.5) 77.9 (87.5) < 0.0001 129.5 (108.8) 87 (96.5) 0.0002