This study examined the association between type 1 diabetes and cancer. The study concluded that type 1 diabetes is associated with differences in the risk of several common cancers. 

The association between diabetes and cancer is not well understood. The majority of previous studies that have looked at diabetes and cancer have not distinguished between type 1 and type 2 diabetes. Most have included primarily patients with type 2 diabetes. Many patients with type 2 diabetes also have other cancer risk factors, such as obesity. Because of this, it is not clear whether cancer risk is increased in patients with type 1 diabetes.

The current study investigated the association between type 1 diabetes and cancer. The study examined patient databases from 5 countries and compared the number of cancers in those with type 1 diabetes to the general population.

A total of 9,149 cancers occurred among those with type 1 diabetes. The risk for all cancers was 1% higher in men and 7% higher in women with type 1 diabetes compared to the general population. When examining specific cancer types, the risk of stomach cancer was 23% higher in men and 78% higher in women. The risk of pancreatic cancer was increased by 53% in men and 25% in women. The increased risk of kidney cancer was 30% in males and 47% in females. The increased cancer risk associated with type 1 diabetes decreased the longer the patient had diabetes.

There was a 44% decreased risk of prostate cancer in males with type1 diabetes and a 10% decreased risk of breast cancer in females with type 1 diabetes compared to the general population. 

This study concluded that type 1 diabetes is associated with differences in the risk of several common cancers. 

A limitation of the study is that the patients included were all relatively young, therefore the researchers were not able to assess changes in cancer occurrence among older people with type 1 diabetes.