1817MO - Effect of a weight loss intervention (WLI) on exercise behaviors in women with breast cancer: Results from the breast cancer weight loss (BWEL) trial

Background

The BWEL trial (Alliance for Clinical Trials in Oncology A011401, NCT02750826) evaluates the impact of a WLI on invasive disease-free survival in breast cancer patients (pts) with a body mass index (BMI) at least 27 kg/m². The WLI was delivered through telephone-based health coaching and focused on caloric restriction and increased exercise. The target exercise goal was 150 minutes (min) of moderate or vigorous physical activity (MVPA) per week (wk). Here we report results of a pre-planned secondary analysis of the BWEL trial evaluating the impact of the WLI on changes in MVPA.

Methods

The first 541 pts enrolled in the BWEL trial were included in a sub-study assessing MVPA at baseline and 6-months via the 7-Day PA Recall Interview. Changes in min of MVPA/wk were compared between groups. Analysis was performed with univariable and multivariable (including study arm, baseline weight, baseline min MVPA/wk, menopausal status, race/ethnicity, and hormone receptor status) regression models. A 2-sided 0.05 level of significance was used.

Results

At baseline, median BMI across the cohort was 32.9 kg/m² (range 26.5, 69.1), median age was 53 (25, 78) years, and median min of MVPA/wk was 0 (range 0, 630; Table). Min MVPA/wk increased significantly in the WLI group (vs control) between baseline and 6 months (median increase of 39.5 [-425, 575] vs 0 [-353, 630] min of MVPA/wk, P=0.0004). At 6 months, 26.4% of WLI vs 36.7% of control pts (p=0.03) engaged in 0 min of MVPA/wk, and 37.0% vs 23.4% engaged in 150+ min/MVPA/wk (p=0.003). MVPA was associated with weight loss; pts across the total cohort who engaged in 150+ min MVPA/wk at 6 months had greater weight loss than pts who did not (mean 4.5% [95% CI: -5.6, -3.4] vs 2.2% [95% CI: -2.9, -1.5], p=0.0005). Table: 1817MO

Minutes of MVPA at baseline and 6-months

Conclusions

A telephone-based WLI significantly increased MVPA in pts with overweight/obesity and early breast cancer. Further follow-up of the BWEL trial will evaluate whether changes in exercise predict cancer outcomes.

Clinical trial identification

NCT02750826.

Editorial acknowledgement

Legal entity responsible for the study

Alliance for Clinical Trials in Oncology.

Funding

U10CA180821, U10CA180882, UG1CA189823; U10CA180863, CCS 707213; U10CA180820; U10CA180868; UG1CA189974. https://acknowledgments.alliancefound.orghttps://acknowledgments.alliancefound.org.

Disclosure

E.D. Paskett: Financial Interests, Institutional, Research Grant: Pfizer, Merck Foundation, Genentech, Guardant Health, AstraZeneca; Financial Interests, Personal, Advisory Board: GSK, Merck. V. Stearns: Financial Interests, Institutional, Research Grant: Abbvie, Biocept, Novartis, Pfizer, Puma Biotechnology, QUE Oncology; Financial Interests, Personal, Advisory Board, Chair or Data and Safety Monitoring Board: AstraZeneca; Non-Financial Interests, Personal, Other, Study assays: Foundation Medicine. T.A. Wadden: Financial Interests, Personal, Advisory Board: WW, Novo Nordisk. All other authors have declared no conflicts of interest.