Four linked papers and an editorial evaluate the evidence on diet, nutrition and physical activity to improve colorectal cancer survival.
2 May 2024
Our latest findings have been published in the International Journal of Cancer (IJC), presenting the latest findings of our Global Cancer Update Programme (CUP Global) – a comprehensive review of the available literature and evidence.
The CUP Global research team at Imperial College London, supported by World Cancer Research Fund International, conducted comprehensive systematic literature reviews and meta-analyses to evaluate the evidence on body fatness, physical activity, sedentary behaviour, and diet with predicted outcomes after a colorectal cancer diagnosis.
Overall, the evidence suggested a physically active lifestyle, a diet rich in plant-based foods, wholegrain foods, and coffee, but avoiding sugary drinks, potentially improve outcomes and overall survival.
The quality of the evidence was independently interpreted and graded by the CUP Global Expert Committee on Cancer Survivorship and Expert Panel. The Panel graded the quality of the strongest evidence as ‘limited-suggestive’ however the rest was graded ‘limited-no conclusion’.
Only very few relevant randomised control trials (RCTs) with relevant exposures were identified. Many of the studies available for review were observational, looking at a relatively small sample over a limited time. The authors and Panel flagged the high risk of possible biases including confounding elements, inaccurate exposure measurements, and selection bias (inclusion only of patients with some accumulated survival time).
The authors and Expert Panel are calling for better-designed intervention trials and large well-designed observational studies with more accurate and repeated exposure and confounder information to strengthen this evidence base. This will allow them to develop improved recommendations for colorectal cancer survivors.
Dr Helen Croker, Assistant Director of Research and Policy at World Cancer Research Fund International, said:
This comprehensive and rigorous review of the current state of evidence offers useful guidance on some of the diet and lifestyle factors that could improve cancer survival, and potentially help people living with and beyond cancer enjoy longer, healthier lives.
At the same time, it shows a clear need for more well-designed intervention and cohort studies to support the development of robust recommendations for colorectal cancer patients and health professionals. As we are seeing an increase of people diagnosed with colorectal cancer at younger ages, it is more important than ever that health advice is based on high-quality research.
Dr Doris Chan, Senior Research Fellow in Nutrition at Imperial College London and Dr Kostas Tsilidis, Reader in Cancer Epidemiology and Prevention at Imperial College London, CUP Global lead researchers, said:
We are delighted that our findings have been evaluated by the Expert Panel and are published today in IJC. We analysed several hundred studies, and although most had limitations and potential biases, we are confident that it represents the best and most up-to-date body of evidence that can assist people living with or beyond cancer in making evidence-based decisions on lifestyle changes that can improve their well-being. We are now moving forward with the next phase of CUP Global, including employing AI-enhanced tools to assist us in our examination of cancer risk factors and prevention strategies.
Professor Dr Rudolf Kaaks, Chair in Cancer Epidemiology at the German Cancer Research Center, is the author of the IJC Editorial that accompanies the papers. He wrote:
Through its international Global Cancer Update Programme (CUP Global) WCRF takes up a central role in organising international expert reviews to summarise the impact of diet, physical activity and excess body weight which provides reliable recommendations on body weight, physical activity and diet in relation to cancer risk.
WCRF and the Imperial College London research team in charge of the CUP Global evaluations are to be commended for their continuing efforts of summarising findings from nutritional epidemiology studies setting highest possible standards for scientific evaluation.
Professor Kaaks’ editorial also refers to a set of linked papers on breast cancer survival, published by the CUP Global team in 2023.
International Journal of Cancer is a bi-weekly peer-reviewed medical journal, and the official journal of the Union for International Cancer Control (UICC).
Dr Sonali Johnson, Head of Knowledge, Advocacy and Policy, Union for International Cancer Control, said:
The Union for International Cancer Control commends the World Cancer Research Fund for its rigorous scientific inquiry, further advancing our understanding of cancer survivorship, as well as improving outcomes and the quality of life of people who have had cancer. This study also underscores the importance of robust research and data in informing protocols, policies and national cancer strategies.
You can read the full papers, via the links below:
Post-diagnosis physical activity and sedentary behaviour and colorectal cancer prognosis: a Global Cancer Update Programme (CUP Global) systematic literature review and meta-analysis.
> Read this paper, published in the IJC
Post-diagnosis adiposity, physical activity, sedentary behaviour, dietary factors, supplement use and colorectal cancer prognosis: Global Cancer Update Programme (CUP Global) summary of evidence grading.
> Read the summary of evidence grading in the IJC
Post-diagnosis adiposity and colorectal cancer prognosis: a Global Cancer Update Programme (CUP Global) systematic literature review and meta-analysis.
> Read this paper, published in the IJC
Post-diagnosis dietary factors, supplement use and colorectal cancer prognosis: a Global Cancer Update Programme (CUP Global) systematic literature review and meta-analysis.
> Read this paper, published in the IJC
Editorial.
All four previously-published papers can be found here
Post-diagnosis body fatness, recreational physical activity, dietary factors and breast cancer prognosis: Global Cancer Update Programme summary of evidence grading.
> Read the paper published in the IJC
Post-diagnosis recreational physical activity and breast cancer prognosis: Global Cancer Update Programme systematic literature review and meta-analysis.
> Read this paper published in the IJC
Post-diagnosis body fatness, weight change and breast cancer prognosis: Global Cancer Update Programme systematic literature review and meta-analysis.
> Read the paper published in the IJC
Post-diagnosis dietary factors, supplement use and breast cancer prognosis: Global Cancer Update Programme systematic literature review and meta-analysis.
> Read this paper published in the IJC
