Dr James Bentham, of the University’s School of Mathematics, Statistics and Actuarial Science, analysed data collected as part of the study led by Imperial College London.
The study found that nearly six per cent of new worldwide cancer cases in 2012 were caused by the combined effects of diabetes and being overweight (BMI of over 25 kg/m2) or obese (BMI of over 30 kg/m2). For the 12 cancers types studied, diabetes and high BMI combined were responsible for nearly 800,000 new cancer cases.
As individual risk factors, being overweight was responsible for twice as many cancers as diabetes, 544,300 cases of cases were attributable to high BMI (equivalent to 3.9 per cent of all cancers), and 280,100 were attributable to diabetes (equivalent to two per cent).
One in four diabetes-related cancer cases in 2012 (77,000 cases) were attributable to the worldwide rise in diabetes between 1980 and 2002. Just under a third of weight-related cancer cases in 2012 (174,000) were attributable to the worldwide rise in the number of overweight and obese people over the same period.
Cancers caused by diabetes and being overweight or obese were almost twice as common in women as men, accounting for 496,700 and 295,900 overall cancer cases respectively.
The researchers say that if global rates of people with diabetes and being overweight continue to rise, the share of cancers attributable to the combined factors will increase by over 30 per cent in women and by 20 per cent in men by 2035.
The research, entitled Worldwide burden of cancer attributable to diabetes and high body-mass index: a comparative risk assessment (Jonathan Pearson-Stuttard et al) was funded by NIHR and the Wellcome Trust. It is published in The Lancet Diabetes & Endocrinology.