CUP Global process for reviewing the literature
There’s a four-step method by which we arrive at new guidance and recommendations. This page explains the first two stages of that process.
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Step 1: Scope of the evidence/Prioritising evidence to review
The current work is organised into 4 areas:
- cancer incidence
- cancer survivors
- cancer mechanisms
- obesity
The mechanisms work supports the cancer incidence and survivors work through developing a clearer understanding of the biological processes that underpin associations between diet, nutrition, physical activity, body weight and cancer.
The work focuses on reviews in specific areas which are expected to add to current understanding of how diet, nutrition, physical activity and body weight influence the development of cancer. Alongside this, we have carried out reviews examining how these risk factors affect outcomes after diagnosis of cancer.
Area 1: Cancer incidence
Reviewing diet, nutrition, physical activity, weight and cancer incidence will continue to be a core element of the work. But rather than reviewing all exposures for every cancer, there will be an increasing focus on systematic scanning of the evidence. This will help us to identify which topics are likely to be fruitful areas of detailed study.
In addition, reviews will be more nuanced, with outcomes examined by cancer subtype, where data allow, rather than considering each cancer as a single disease.
There will also be several collaborative projects to expand the work into new areas, including the impact of different dietary and lifestyle patterns and of diet, nutrition, physical activity and weight exposures over the lifecourse.
Area 2: Cancer survivors
We want to focus on the impact of diet, nutrition, physical activity and weight on long-term health after a cancer diagnosis. This will begin with a series of reviews for breast cancer, and reviews on colorectal cancer and prostate cancer will follow.
There will also be specific reviews to determine the impact of diet, nutrition, physical activity and weight on children from cancer diagnosis and into adult life. The first review will be on paediatric acute leukaemia.
Area 3: Cancer mechanisms
We aim to develop a clearer understanding of the biological processes that underpin associations between diet, nutrition, physical activity, weight and cancer.
This will be done by reviewing both human and experimental data and will support both the cancer incidence and cancer survivor reviews.
Area 4: Obesity
Obesity was identified as a key risk factor for cancer in the Third Expert Report, increasing the risk of numerous cancers.
This work aims to ensure that our Cancer Prevention Recommendations relating to obesity remain up to date, with the potential to develop more specific recommendations.
Step 2: Gathering the Evidence – SLRs
Epidemiological reviews
WCRF International works with collaborators who undertake systematic literature reviews in research areas identified in step 1.
The CUP Global team at Imperial College London undertake many of the CUP Global cancer incidence and survivorship reviews, although we also work with other collaborators on reviews in specialist areas, for example dietary and lifestyle patterns research and life course research.
The reviews on cancer incidence include observational studies (primarily prospective cohort studies) and intervention studies which examine how diet, nutrition, physical activity and body weight influence the risk of developing a wide range of cancers.
Research has historically focused on understanding exposures influencing cancer development but there is a growing literature on diet, nutrition, physical activity and body weight as levers for improving post-diagnostic survival and quality of life.
Our reviews on cancer survivorship includes studies examining the effect of post-diagnosis diet, physical activity and body weight on all-cause mortality, cancer-specific mortality, cancer recurrence and second primary cancers.
We also undertake reviews on studies with wellbeing outcomes (quality of life and cancer-related fatigue) as these are key outcomes of importance for people living with and beyond cancer.
Reviews are carried out using standard systematic review methodologies according to pre-specified protocols.
- The protocols for the cancer incidence work were developed by Imperial College London.
- The protocols for the cancer survivorship reviews were developed by the research team at Imperial College London with input from a Protocol Expertise Group convened by WCRF International.
The relevant information identified in these reviews is added to the CUP Global database, this means that the process of updating reviews is efficient since we are able to use the existing information from the database and simply add the findings from more recent studies as the work goes forwards.
Building state of the art methods for reviewing evidence into CUP Global
WCRF International is collaborating with computer scientists at the University of Bristol who are working with the CUP Global team at Imperial College London on a project to refine the systematic reviews methods used in CUP Global.
The project aims to improve the efficiency of the CUP Global software pipeline and explore the potential of automation or semi-automation of tasks.
The project will develop a new user interface that facilitates the workflow and data management of the systematic review process, complemented by algorithms that automate the aspects of article selection, data extraction and risk of bias assessment.
> Find out more about their project
Mechanistic reviews
Evidence of the presence or absence of plausible biological pathways linking dietary factors and body fatness to cancer-related outcomes is essential to draw causal inferences.
WCRF International works with collaborators at the International Agency for Research on Cancer (IARC) towards identifying what those biological pathways might be.
All relevant scientific literature published globally is identified, collated and synthesised following guidance from a standardised Framework consisting in a combination of automated search tools and expert inputs from both IARC and the CUP Global Mechanisms Expert Committee.
This investigation work draws primarily from human studies, but experimental studies, including animal or in vitro studies, are also used as supportive evidence.
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Experts we work with
We collaborate with world-renowned experts to assess every aspect of CUP Global