Type 1 diabetes can increase risk of certain cancers, says study

Having type 1 diabetes can increase the risk of developing some types of cancer, according to a multinational study.
Previous research has investigated the relationship between type 2 diabetes and cancer, but very few studies have explored the incidence of cancer in type 1 diabetes.
In this new study, researchers analysed five national diabetes registers from Scotland, Denmark, Swede, Finland and Australia. Overall, 9,149 cases of cancer in people with type 1 diabetes were identified, of whom the average patient age was 51 years. These cases were then compared to the estimated cancer incidence in the general population.
Type 1 diabetes patients were found to have a higher risk of developing cancer in the pancreas (53 per cent in men, 25 per cent in women); kidney (30 per cent in men, 47 per cent in women); stomach (23 per cent in men, 78 per cent in women); liver (100 per cent in men, 55 per cent in women); and endometrium (42 per cent in women).
The overall risk of cancer was to be found to be just 1.0 per cent higher in men with type 1 diabetes and 7.0 per cent higher in women with type 1, compared to the population at large. But when data was removed for sex-specific cancer types (breast, prostate, testis, cervix, endometrium and ovary), men with type 1 diabetes had an increased 15 per cent risk; women had an increased 17 per cent risk.
However, the findings indicate that people with type 1 diabetes are less likely to develop prostate, ovary and breast cancer.
The relative rates of cancer were found to generally decrease with increasing duration of diabetes. The researchers hypothesised that having too high blood sugar levels over a long period of time could increase the risk of certain cancers.
They wrote: “Hyperglycemia may be a plausible explanation given the identification of a dose-response relationship between glycated hemoglobin levels (HbA1c) and the risk of certain cancers.”
The findings were published in the journal Diabetologia.