Patients with type 2 diabetes have a significantly higher risk of developing cancer. However, the risk in women and men is influenced very differently and not all cancer entities are affected equally, as a large population study from China has shown.
It has been known for some time that type 2 diabetes can increase the risk of cancer. Possible causes include hyperinsulinemia, obesity, chronic inflammation, and elevated blood sugar levels. A study by Chinese researchers led by first author Jiying Qi of the Jiao Tong University School of Medicine, Shanghai, China, provides new figures.
The study evaluated data from 410,191 adult patients between the ages of 20 and 99 who had type 2 diabetes between July 2013 and December 2016 and did not have cancer at that time. The Shanghai scientists then tracked the medical records until 2017 to compare the incidence of newly diagnosed cancers with peers without diabetes.
By the end of 2017, a total of 8,485 cancer cases had been recorded. It was found that men with type 2 diabetes had a 34% higher overall cancer risk than their healthy peers and that women even had a 62% higher risk. Men with type 2 diabetes had a higher risk of 11 different types of cancer, while women had a higher risk of 13 different types of tumors.
In men with type 2 diabetes, the main finding of this study was an 86 percent increase in the risk of prostate cancer. They also had a significantly higher risk of leukemia, skin cancer, thyroid cancer, lymphoma, kidney cancer, liver cancer, pancreatic cancer, lung cancer, colorectal cancer, and gastric cancer. However, men with type 2 diabetes were found to have a lower risk of esophageal cancer than men without diabetes.
Women with type 2 diabetes had the highest risk of nasopharyngeal carcinoma, more than twice as high as their peers without diabetes (RR 2.03). They also had a higher risk of liver, esophagus, thyroid, lung and pancreatic cancer, lymphoma, uterine cancer, colorectal cancer, leukemia, breast cancer, cervical cancer, and gastric cancer. In contrast, the risk of developing gallbladder cancer was comparatively low in women with type 2 diabetes.
For many cancer entities, women and men with type 2 diabetes have a significantly increased risk. The authors write that the usual cancer screening examinations for early detection might not be sufficient for these patients. Suitable strategies should be developed for the early detection of cancer in type 2 diabetics.
Source:
Jiying Qi et al; Cancer risk among patients with type 2 diabetes: A real-world study in Shanghai, China; J Diab (2019); DOI: https://doi.org/10.1111/1753-0407.12926