Type 1 diabetes associated with increased risk of cancer

Certain forms of cancer occur more often in patients with type 1 diabetes compared with the general population in the corresponding sex and age groups. This has been shown in a new Swedish study from Karolinska Institutet.

The study, which has been published this week, is the first large-scale investigation of the risk of cancer among patients with type 1 (youth onset) diabetes. It included nearly 30,000 patients who had been treated at hospitals between 1965 and 1999. Of these, 355 received a cancer diagnosis, which represents 20 percent more than would be expected in the Swedish population of the corresponding sex and age. Increased risk was shown specifically for cancer of the stomach, cervix, and womb. On the other hand, no increase in risk was apparent regarding cancer of the breast, colon/rectum, or kidney. Nor was there any rise in the risk of developing cancer of the pancreas, which was observed in patients with type 2 (adult onset) diabetes.

Diabetes is actually two diseases, with different causes and mechanisms. The most common type is adult onset diabetes (type 2), which usually appears in mature adults. The other variety is type 1, with its onset occurring in childhood or adolescence. Thus far there have been very few individuals with type 1 diabetes among those reaching cancer age, since treatments available in the first two thirds of the 20th century were unable to prevent the complications leading to early death. However, with today’s careful monitoring and treatment, the length of patients’ lives has increased dramatically.