# BWEL (Breast Cancer Weight Loss, Alliance A011401)

Source: https://onco.cc/trials/bwel/  
OnCo record `bwel` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

BWEL is a trial of more than 3,000 women testing whether losing weight after breast cancer treatment reduces recurrence. The programme achieved weight loss; the effect on recurrence was not clearly shown at the first analysis.

## Summary

BWEL randomised 3,181 women within 12 months of diagnosis to a two-year telephone-delivered lifestyle programme (calorie restriction, 150-225 minutes of moderate activity per week, 42 coaching calls) plus health education, or health education alone; the primary endpoint was invasive disease-free survival. The intervention produced significantly greater weight loss at 12 and 24 months than the control arm. Primary efficacy results were presented in late 2025 and reported as not demonstrating a statistically significant improvement in invasive disease-free survival at the planned analysis; full peer-reviewed publication and longer follow-up are awaited, and the effect sizes below should be checked against the publication when available. Interpretation is contested: the weight loss achieved was modest (a few percent of body weight), follow-up is relatively short for HR-positive disease, and secondary cardiometabolic and quality-of-life benefits were seen. BWEL is the largest lifestyle-intervention trial ever run in cancer survivors and its design (telephone coaching, scalable) remains the template.

## Fields

- Kind: Trial
- Status: mixed
- Last checked: 2026-09-08
- Registry id: NCT02750826
- Phase: 3
- Setting: Stage II-III HR-positive or HER2-positive breast cancer, BMI at least 27: 2-year telephone-based weight-loss intervention plus health education vs health education alone
- Sponsor: Alliance for Clinical Trials in Oncology / NCI
- Enrolled: 3181
- Result: Weight loss achieved; primary iDFS endpoint not met at first analysis (presented 2025; publication pending, verify).
- Outcomes: Invasive disease-free survival: Telephone weight-loss intervention + health education vs Health education alone; Weight change from baseline at 1 year: Telephone weight-loss intervention + health education -4.7% vs Health education alone 1%
- Replication: Weight loss reproduces the LISA trial (letrozole-treated women) and the SUCCESS-C lifestyle arm; whether it changes breast cancer recurrence remains untested pending the BWEL primary analysis.

## Notes

- Record written before the peer-reviewed primary publication; numerical results deliberately omitted.

## Sources

- ClinicalTrials.gov NCT02750826: https://clinicaltrials.gov/study/NCT02750826
- BWEL design paper (npj Breast Cancer 2017): https://doi.org/10.1038/s41523-017-0040-8

## Connected records

- ideas: [GLP-1 receptor agonists as adjuvant weight-loss therapy in HR-positive breast cancer](https://onco.cc/ideas/idea-nl-glp1-adjuvant-hr-breast/)
- cancers: [HER2-positive breast cancer](https://onco.cc/cancers/breast-her2-positive/), [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/)
- fronts: [Diet, Exercise & Lifestyle](https://onco.cc/fronts/nutrition-lifestyle/)
- technologies: [Dietitian-led weight-loss programmes in HR-positive breast cancer](https://onco.cc/technologies/dietitian-led-weight-loss-breast/), [Endocrine therapy (SERMs, AIs, SERDs)](https://onco.cc/technologies/endocrine-therapy/), [Exercise & lifestyle oncology](https://onco.cc/technologies/exercise-oncology/)
- companies: [Alliance for Clinical Trials in Oncology](https://onco.cc/companies/alliance-oncology/)
- institutions: [Dana-Farber Brigham Cancer Center](https://onco.cc/institutions/dana-farber/)
- terms: [Decentralised trial](https://onco.cc/terms/decentralised-trial/), [Energy balance](https://onco.cc/terms/energy-balance/), [Event-free / disease-free survival (EFS, DFS, iDFS, RFS)](https://onco.cc/terms/efs/), [Obesity-related cancers (IARC list of 13)](https://onco.cc/terms/obesity-related-cancers/), [Pragmatic trial](https://onco.cc/terms/pragmatic-trial/)
- bottlenecks: [Failures are hidden](https://onco.cc/bottlenecks/b-negative-results/), [Survivorship and late effects are neglected](https://onco.cc/bottlenecks/b-survivorship/)
- key papers: [Randomized phase III trial evaluating the role of weight loss in adjuvant treatment of overweight and obese women with early breast cancer (Alliance A011401): study design](https://onco.cc/key-papers/paper-ligibel-npj-breast-cancer/)
- roadmaps: [Diet, exercise and lifestyle roadmap: causes established → interventions that disappointed → exercise proven as treatment](https://onco.cc/roadmaps/nutrition-lifestyle-roadmap/)

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