The Diabetes – Cancer Link

Pre-existing diabetes may increase the death risk of cancer patients; this excess mortality is larger among patients with diabetes treated with insulin. Kristina Ranc, from the Steno Diabetes Center (Denmark), and colleagues assessed all patients diagnosed with cancer in Denmark between 1995 and 2009 -- a total of 426,129 patients had incident cancer and 42,205 had diabetes before their cancer diagnosis. The team found that cancer patients with diabetes had higher overall mortality than those without diabetes, and this was the case for all cancers combined as well as for most individual cancer sites.  Further, the researchers found that the risk appeared highest for diabetic cancer patients treated with oral diabetes drugs or insulin, and when assessed further, insulin-treated patients were at highest risk. Observing that: “Our study provides strong evidence that cancer patients with pre-existing diabetes experience higher mortality than cancer patients without diabetes,” the study authors posit that: “The higher mortality seen among cancer patients treated with [oral diabetes drugs] or insulin is in accordance with the existing evidence that more intensive diabetes treatment reflects a larger degree of comorbidity at the time of cancer diagnosis, and hence poorer survival.”