Obesity Prevention in Children and Young People Treated for Acute Lymphoblastic Leukaemia with ALLTogether

Background Leukaemia is the most common cancer in children with 800 diagnoses per year in England. To survive, children need strong treatments like chemotherapy and steroids given usually through clinical trials. The current trial used by the NHS is called ALLTogether. Fifty percent of children become obese during treatment due to increased hunger, cravings for junk foods and lack of physical activity. Obesity raises the chance of cancer relapse by 31%, makes treatment side-effects worse and makes it harder to kill off leukaemia cells, which affects how well children do during treatment, as indicated by minimal residual disease, a key predictor of prognosis.

Aims and Objectives This study (called BREVARY) aims to see if we can successfully provide personalised diet and physical activity with behaviour support for children and young people with leukaemia who are being treated with the ALLTogether trial. It will help us figure out if we can perform a bigger study, if this programme could reduce obesity and side-effects and improve survival and wellbeing.

How it will be done We plan to randomly assign participants to one of three groups; one group will get both a diet and physical activity plan, another will get only a diet plan, and the last group will receive standard care. This will take place in Hospital Infantil Universitario Nino Jesus, Madrid and Bristol Royal Hospital for Children and Southwest England NHS-sites. The diet and exercise plans will be created in partnership with the children and their families and delivered online or during regular hospital visits. The diet will follow healthy eating guidelines, consider personal food preferences (including cultural and religious needs), treatment side-effects and personal finances. Assessments of fitness and strength will be taken to plan personalised activities. During the study, the following data will also be collected: weight, height, body fat, diet, biomarkers, microbiome, muscle strength and wellbeing at three different times. "One to one" interviews will be conducted at the end to obtain feedback on their experiences with BREVARY.

This study aims to find out if children and their families/carers are willing to participate in BREVARY, if enough people sign up and stay until the end and if our interventions and health measurements are appropriate.

Potential Impact The results will help determine if a larger study can be performed, if changes are needed and what the cost will be. The study will be disseminated through networks, targeting underserved communities, healthcare professionals and affected families using accessible platforms to spread the word.