With cases of diabetes rocketing across many parts of Asia, researchers looked into the relationship between T2D and cancer deaths across cohort studies conducted in China, Taiwan, Singapore, South Korea, Japan, India and Bangladesh.
They focused on the data of over 750,000 people, with an average age of 53.9 years at the start of a study. A total of 37,343 cancer deaths were identified during a mean follow-up time of 12.7 years.
The authors found that having T2D led to a 26% increase in the risk of dying from any form of cancer, even when taking into account factors such as BMI, alcohol consumption and smoking.
Like in the West, they also found statistically significant links between T2D and the risk of death from specific cancers, showing increased risk of death from cancers of liver, pancreas, bile duct, colorectum, and breast associated with T2D.
The strongest association was observed for cancers of the liver, thyroid and kidney (double the risk in each case), and endometrium (2.7 times increased risk) and breast (1.7 times increased risk), relative to individuals who did not have T2D.
Greater risk for Asians
The research conducted by Dr Yu Chen, Associate Professor of Epidemiology at the Department of Population Health at New York University School of Medicine, as well as researchers from institutes across America and Asia, said most previous studies had looked only at Western populations.
But with diabetes becoming increasingly prevalent throughout Asia, they added it was important to understand whether the risk of developing cancer in Asians with T2D is similar to that seen in the West, or whether they face different risks than white western populations.
For certain site-specific cancers including kidney, thyroid, and prostate cancer, they found there was evidence that T2D has a greater effect on risk in Asians than in people of European extraction. In addition, the risk of death from cancer in general was higher in individuals with T2D who were under 60 years old at the start of a study.
However, the overall risk of cancer, digestive cancers and breast cancer was found to be largely similar in Asians and in developed Western countries.
They add: “Taken together, given the magnitude of the associations and the consistent data across different studies and populations, T2D should be considered as a risk factor for cancers in Asians, especially for liver cancer which has a high incidence in Asians”
A major strength of this study, published in the journal Diabetologia, was its large sample size of diverse Asian populations, which allowed for a detailed analysis that could take into account differences in factors such as sex, age, smoking status and alcohol consumption. It was also the first study of its kind to investigate the influence of T2D on cancer in South Asians.
The authors concluded: “The findings indicate a potential need for appropriate cancer screening among individuals with T2D, and a greater emphasis on lifestyle modifications to prevent T2D and reduce cancer mortality, not only in Western populations, but also in Asians.”