Approximately 4% of New Cancers Worldwide Attributed to High BMI
In a population-based study reported in The Lancet Oncology, Arnold et al estimated that 3.6% of all new cancers worldwide in 2012 were attributable to high body mass index (BMI). The proportions of such cases were greater in women than in men and in highly developed vs less-developed countries.
Study Details
In the study, population-attributable fractions for BMI-related cancer were derived using relative risks and BMI estimates in adults by age, sex, and country. A 10-year lag period was assumed between high BMI (≥ 25 kg/m2) and cancer occurrence. BMI estimates from 2002 were from the Global Burden of Metabolic Risk Factors of Chronic Diseases Collaborating Group, and GLOBOCAN2012 data were used to estimate the numbers of new cancer cases attributable to high BMI.
3.6% of All New Cancers
It was estimated that 481,000, or 3.6%, of all new cancer cases in adults (aged ≥ 30 years after the 10-year lag period) in 2012 were attributable to high BMI, including 12.8% of all high BMI–related cancers (ie, esophageal adenocarcinoma and colon, rectal, kidney, pancreatic, gallbladder, postmenopausal breast, corpus uteri, and ovarian cancers). Estimates were 5.4% in women (345,000 cases) and 1.9% in men (136,000 cases). Corpus uteri, postmenopausal breast, and colon cancers accounted for 63.6% of cancers attributable to high BMI.
Higher in Developed Countries
The proportions of attributable cases were higher in countries with very high (5.3%) and high (4.8%) human development indices than in those with moderate (1.6%) and low (1.0%) indices. For example, the North American region contributed the most cases attributable to high BMI (111,000, or 23.0%, of total cases), whereas sub-Saharan Africa contributed the least (7,300, or 1.5%).
It was estimated that if population BMI had remained at levels recorded in 1982, approximately one-quarter (118,000) of new cases of high BMI–related cancers would have been prevented in 2012. Thus, it is estimated that approximately 0.9% of all cancers diagnosed in 2012, including 0.5% in men and 1.3% in women, could have been prevented by avoidance of high BMI.
The investigators concluded: “These findings emphasize the need for a global effort to abate the increasing numbers of people with high BMI. Assuming that the association between high BMI and cancer is causal, the continuation of current patterns of population weight gain will lead to continuing increases in the future burden of cancer.”
Melina Arnold, PhD, of the International Agency for Research on Cancer, Lyon, is the corresponding author for The Lancet Oncology article.
The study was funded by the World Cancer Research Fund International, European Commission, Australian National Health and Medical Research Council, and the National Institutes of Health. The study authors reported no potential conflicts of interest.
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