Associations between preoperative weight and body composition changes and surgical outcomes in patients with obesity and gastrointestinal cancer: a protocol for a prospective observational study in the active together cancer prehabilitation service

Introduction

The impact of preoperative weight loss and body composition changes on surgical and patient-reported outcomes remains unclear in gastrointestinal cancer patients. Prehabilitation programmes integrating exercise, nutrition and psychological support can improve surgical readiness and recovery but the role of body mass and composition changes within such services is not well understood. This study aims to investigate the associations between preoperative changes in body mass and composition and surgical, physical fitness, nutritional and quality of life outcomes among people with obesity undergoing surgery for upper gastrointestinal or colorectal cancer within the context of a cancer prehabilitation service (Active Together).

Methods and analysis

This prospective observational study will recruit 100 adults (≥18 years; body mass index ≥30 kg/m²) scheduled for curative upper gastrointestinal or colorectal cancer surgery and enrolled in the Active Together prehabilitation service. Participants will attend two study visits: one as soon as possible after diagnosis and one within 2 weeks before surgery. Participants will undergo body mass, composition and size measurements and complete questionnaires on their nutritional status and quality of life. Routinely collected surgical outcomes (complications, operative approach and duration, length of hospital stay, readmissions, 1-year survival) and Active Together assessment data (physical fitness, psychological well-being, nutritional status) will also be collected. Correlation analyses and regression models will be used to explore the associations between preoperative changes in body mass and composition and surgical, physical fitness, nutritional status and quality of life outcomes.

Ethics and dissemination

Ethical approval has been obtained from the Health Research Authority (Integrated Research Application System project ID 361634; Research Ethics Comittee reference 26/YH/0019). Written informed consent will be obtained from all participants. Data will be processed in accordance with General Data Protection Regulations and the Data Protection Act 2018. Findings will be disseminated via peer-reviewed publications, conference presentations and patient and public involvement activities.