By Amy Orciari Herman
The association between diabetes and cancer is strongest right after diabetes diagnosis, according to a Cancer study. This finding, the researchers say, suggests that “epidemiologic associations between diabetes and cancer can be partially explained by a detection bias around the time of a diabetes diagnosis.”
Using Canadian healthcare databases, the researchers matched over 516,000 adults with newly diagnosed diabetes to 516,000 nondiabetic controls. During a median 5 years after diabetes diagnosis (or matched date), some 36,000 incident cancers were identified in those with diabetes and 33,000 in controls. Those with diabetes had a 62% higher cancer risk in the first 3 months after diabetes diagnosis; however, they showed no elevated risk thereafter.
In addition to the findings suggesting detection bias, patients with diabetes were 23% more likely to be diagnosed with cancer in the 10 years before diabetes diagnosis, relative to controls. “This observation,” the authors note, “may be due to shared metabolic risk factors for diabetes and cancer that are present during the prediabetes period, such as insulin resistance and hyperinsulinemia.”