Meanwhile, certain lifestyle factors, such as being overweight and sedentary, are risk factors for both type 2 diabetes and cancer.
These authors did a meta-analysis of 15 previous trials that had looked at cancer in diabetic patients.
Individuals who had been diagnosed with diabetes before their cancer surgery had a 50 percent higher chance of dying in the month after their operation compared with non-diabetic patients. This was after accounting for other factors.
There were no studies in the mix that looked at breast or endometrial cancer, so it could not be determined if there might be a link between these two as well.
It was unclear why this might be the case, but the authors had some hypotheses.
"Diabetes increases the risk of infection from surgery. High blood sugar and diabetes [increase] infections, period, with or without cancer," said Yeh, who is an assistant professor of general internal medicine and epidemiology at Johns Hopkins University School of Medicine in Baltimore.
Also, she said, diabetes is a risk factor for cardiovascular disease and surgery increases the risk of blood clots, making diabetics doubly at risk for heart problems during surgery.
"What we would like to do [now] is set up research to test if better diabetes management can reduce the risk of mortality in cancer patients [undergoing surgery]," said Yeh.
Visit the American Diabetes Association for more on living with diabetes.
SOURCES: Hsin-Chieh "Jessica" Yeh, Ph.D., assistant professor, general internal medicine and epidemiology, Johns Hopkins University School of Medicine, Baltimore; Martin S. Karpeh Jr., M.D., chairman, surgery, Beth Israel
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