Patients with type 1 and type 2 diabetes have an increased risk of developing and dying from cancer, according to a study published in Diabetes Care.
Patients with type 2 diabetes in particular had an increased risk of developing almost every type of cancer compared to the general population, reported Jonathan E. Shaw, MD, of the Baker IDI Heart and Diabetes Institute in Melbourne, and colleagues.
Previous evidence has suggested that patients with type 2 diabetes have an increased risk of developing particular cancers. The researchers wanted to determine the risk of site-specific cancer for people with type 1 and type 2 diabetes compared with the general population.
The study included 953,382 participants from a National Diabetes Registry between 1997 and 2008, who were linked to national death and cancer registries in Australia.
The researchers found that people with type 1 diabetes had an increased risk for cancer of the pancreas, liver, and esophagus. Females with type 1 diabetes also had an increased risk for colorectal, stomach, thyroid, brain, lung, endometrial, and ovarian cancers.
Patients with type 1 diabetes had increased rates of mortality from pancreas, liver, kidney (males only), brain (females only), and endometrium cancers as well as non-Hodgkin’s lymphoma.
For patients with type 2 diabetes, the risk of developing almost all cancers was significantly higher than the general population, especially for the liver and pancreas. They also had an increased rate of mortality for liver, pancreas, and kidney cancers in addition to Hodkin’s lymphoma. Females with type 2 diabetes had additional increased rates of mortality for gallbladder and stomach cancers as well as non-Hodgkin’s lymphoma.
Both patients with type 1 and type 2 diabetes had lower risks of developing melanoma and prostate cancer than the general population.
Because the incidence and mortality of cancers is higher in patients with diabetes, the researchers emphasized the importance of screening these patients for cancer.
OBJECTIVE Evidence indicates an increased risk of certain cancers among people with type 2 diabetes. Evidence for rarer cancers and for type 1 diabetes is limited. We explored the excess risk of site-specific cancer incidence and mortality among people with type 1 and type 2 diabetes, compared with the general Australian population.
CONCLUSIONS Type 1 and type 2 diabetes are associated with an excess risk of incidence and mortality for overall and a number of site-specific cancers, and this is only partially explained by bias. We suggest that screening for cancers in diabetic patients is important.