An article was published in Diabetologia, which revealed that patient having a pre-existing diabetes had a greater risk of death and this was highest when observed in those using insulin. This was a Danish study which found that patients who had diabetes for 2 years, and who had been treated with insulin at the time of cancer diagnosis, had a mortality rate that was about 4 times higher than that of non diabetics. Among 426129 patients with cancer, 42205 patients were having diabetes prior to their cancer diagnosis. Diabetic had a poor survival as compared to non diabetic and this difference was more marked when compared to diabetics on insulin.
Various co-morbidities associated with diabetes may be one of the reasons but there may be a “Direct Effect” from glucose lowering regimens that induce a “More Progressive Cancer At Diagnosis &/or Impaired Prognosis". Although author emphasise that the study is entirely observational so no definitive conclusion can be drawn and only trends are observed and hypothesis is generated for future studies.