Policy and Preventability

Making it Easier to Make Healthy Choices

AICR asked the expert panel behind the 2007 Expert Report – and its 10 Recommendations for Cancer Prevention – to lend their understanding of the science of cancer prevention to develop a report on cancer prevention policy. They were joined in that task by leading policy experts specializing in the fields of physical activity, economics, and the psychology of health behaviors.

Evidence for the policy report came partly from two systematic literature reviews that investigated two specific questions:

What factors shape the patterns of behavior that affect cancer risk (namely diet, physical activity and body fatness)? And, around the world, what effects have specific interventions had on those patterns of behavior?

The policy report also estimated how much cancer could be prevented through diet, physical activity and weight management.

Preventability estimates were calculated using information on:

• Cancer risk associated with lifestyle factor
• Prevalence of low, moderate and high levels/consumption of lifestyle factor in each country
• Incidence of different cancers in each country

You can read the full methodology used to calculate the estimates in Appendix A of the Policy Report.

Briefly: Estimates were made for lifestyle factors judged to be convincing or probable modifiers of cancer risk in the report and its continuous updates, with a few exceptions; thus 12 cancers were included.

Highest versus lowest risk estimates were used for cancer risk. One research study (ideally large and recent) was chosen from those collected as part of the 2007 report and its continuous updates, where the size of effect was representative of all studies. Information on prevalence of lifestyle factors was obtained from national surveys. These two pieces of information were used to estimate preventability for each lifestyle factor.

How Many Cancers Are Preventable?

For the 12 common cancers, about 35 percent of cases in the United States are preventable through a healthy diet, being physically active and maintaining a healthy weight. This translates to about 340,000 preventable cases of cancer.

Estimates for other countries is 37 percent for the United Kingdom, 30 percent for Brazil and 27 percent for China.

The updated figures confirm that about a third of the most common cancers in higher-income countries and about a quarter in lower-income countries could be prevented through eating healthily, being physically active and maintaining a healthy weight.

Limitations

These figures are estimates and not precise values. They are likely to be underestimates as only those cancers judged to be convincingly or probably linked to lifestyle factors are included.

For the 2009 Policy Report, these estimates were based on GLOBOCAN 2002 data. In February of 2011, those original estimates were been updated with the most recent global incidence data from GLOBOCAN 2008* on cancer rates.

In order to estimate how preventable cancer is in different parts of the world figures were calculated for two high-income countries (USA and UK), a middle-income country (Brazil) and a low-income country (China).

* Ferlay J, Shin HR, Bray F, Forman D, Mathers C and Parkin DM. GLOBOCAN 2008, Cancer Incidence and Mortality Worldwide: IARC CancerBase No. 10 [Internet]. Lyon, France: International Agency for Research on Cancer; 2010. Available from: http://globocan.iarc.fr]