Preventability estimates are required so that policy-makers can assess the impact of different approaches to reduce cancer risk.
It is important to identify how many cases of cancer could be prevented by changes to the foods we eat and the amount of physical activity we do.
The original estimates on the preventability of cancer and the methods used to calculate them were published in the Policy Report. These estimates are based on the 10 Cancer Prevention Recommendations.
These original estimates have now been updated with new data from:
GLOBOCAN 2012 on cancer rates(1)
Continuous Update Project for cancers of the breast, colorectum, pancreas, endometrium, ovary, prostate, liver, gallbladder, kidney and stomach(2)
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).
(1) Ferlay J, Soerjomataram I, Ervik M, Dikshit R, Eser S, Mathers C, Rebelo M, Parkin DM, Forman D, Bray F. GLOBOCAN 2012 v1.1, Cancer Incidence and Mortality Worldwide: IARC CancerBase No. 11 [Internet]. Lyon, France: International Agency for Research on Cancer; 2013. Available from: http://globocan.iarc.fr, accessed on 23/01/2015.
(2) Details provided in footnotes to tables on diet, nutrition, body fatness and physical activity; and body fatness
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
However, in brief the estimates were made for lifestyle factors judged to be convincing or probable modifiers of cancer risk in the Continuous Update Project or Second Expert Report with a few exceptions; thus 13 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 Continuous Update Project or Second Expert Report, 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.
The information on incidence of cancer was used to provide an overall estimate of preventability for each country.
Cancer preventability was estimated for the combination of risk factors related to diet, nutrition, body fatness and physical activity and also separately for body fatness.