The methodology behind the Policy and Action for Cancer Prevention Report

The World Cancer Research Fund (WCRF) and the American Institute for Cancer Research (AICR) Report Policy and Action for Cancer Prevention is a companion to the Second Expert Report Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective which was published in 2007. The Second Expert Report included a rigorous review of the evidence on food, nutrition (including body fatness) and physical activity, and cancer. Non-starchy vegetables and also fruits were judged to probably protect against cancers of the mouth, pharynx and larynx, the oesophagus, and the stomach. Also, fruits were judged to probably protect against lung cancer. One of the Report’s recommendations is that people should eat at least five portions/servings of a variety of non-starchy vegetables and fruits every day. In total there are 10 recommendations; the others include being physically active, maintaining a healthy body weight and limiting alcohol, red meat and salt consumption and avoiding processed meat (http://www.dietandcancerreport.org).

The aim of the Policy Report is to make robust evidence-based recommendations for policies and actions that will help achieve the recommendations of the Second Expert Report and thereby help to prevent cancer worldwide (http://www.dietandcancerreport.org/pr/). Two systematic literature reviews of the evidence were commissioned from independent research institutions. All types of evidence were reviewed. The first reviewed the evidence about what affects our dietary patterns and the amount of physical activity we do. It also reviewed evidence relating to interventions aimed to change or maintain behaviour (such as studies aiming to increase intake of vegetables and fruits). The second reviewed the effectiveness of population and community interventions to prevent cancer through food, nutrition, or physical activity. Additional information obtained from Panel members, peer reviewers and independent organisations was utilised. The Policy Report also includes new estimates for how much cancer can be prevented by eating a healthy diet, being physically active and maintaining a healthy body weight. If everyone had the same dietary and physical activity patterns as those who have the best diets and do the most physical activity, then about one third of the most common cancers could be prevented in high-income countries. In low and middle-income countries about one quarter of the most common cancers are preventable.

A Panel of 23 international experts considered the evidence. The Panel comprised experts who examined the evidence for the Second Expert Report and an additional three with specific expertise in policy. Its collective expertise included public policy, economics, psychology, physical activity, nutrition, cancer, obesity, other chronic diseases, epidemiology, biochemistry, statistics, and public health. The Panel included relevant World Health Organization expert consultations, as well as observers from six relevant United Nations and other international organisations.

The Policy Report is divided into three parts. Part one outlines the physical environmental, economic and social determinants of health and disease, including cancer. It also puts forward a ‘case for action’ that shows that as the size and average age of populations increase, the numbers of cases of cancer are expected to increase. Part two summarises the evidence on determinants of patterns of diet, physical activity and body fatness under four main themes: physical environmental, economic, social, and personal. Promising policy and action options are identified. The Panel’s recommendations for policies and actions likely to help prevent cancer can be found in Part three. The Panel considered all the evidence and then made 48 recommendations directed at nine different actor groups, ranging from governments to people. The actors can use the recommendations to make changes that will help to prevent cancer, as well as other chronic diseases such as cardiovascular disease, diabetes and obesity. All the recommendations are important. Some are more ambitious than others. Some can bring quick benefits, while others are likely to be effective in the longer term. The Policy Report emphasises that promoting public health is not just the responsibility of health departments, but is shared by all sections of society. All the actors will need to work together in order for changes in society to happen.