Women with Type 1 Diabetes at Higher Cancer Risk

A new study finds a link between type 1 diabetes and differences in the risk of several common cancers, with type 1 diabetic women at a slightly higher cancer risk than the general population.

A team of researchers used data from 5 nationwide diabetes registers—Australia, Denmark, Finland, Scotland, and Sweden— to study a total of 9,149 cases of first-incidence cancer out of 3.9 million person-years. All type 1 diabetes patients studied in the analysis were diagnosed before age 40, and were followed until the first cancer occurrence, death, or the end of the study. Diabetic patients were compared to the total background population, and not to the non-diabetic population, due to the low prevalence of type 1 diabetes in the population. The median age of cancer diagnosis was 51, according to the authors.
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Overall, more than 85% of patients with type 1 diabetes were later diagnosed with cancer, and the risks of cancer were greatest after the first year of diagnosis, with risks decreasing after the first year. Among women, the risk was the same as the general population after 5 years, while men’s cancer risk was the same as the general population after 20 years. The authors found that diabetic patients with cancer had higher incidence of stomach cancer, liver cancer, pancreatic cancer, endometrium cancer, and kidney cancer. Diabetic patients, however, were found to be at lower risk of prostate cancer and breast cancer, the researchers note.

Based on the findings, the authors “do not recommend any changes to current practice, whether that be for male or female patients” with diabetes, says Stephanie Read, PhD, a research fellow at the University of Edinburgh’s Usher Institute of Population Health Sciences & Informatics, and a co-author of the study.

Lifestyle approaches to mitigate cancer risk, including avoiding smoking, maintaining a healthy weight, and increasing physical activity, “apply to people with type 1 diabetes [the same] as they do to the general population,” says Read, adding that further research is needed to “identify the explanation for the increased risk of some cancers among people with type 1 diabetes, and whether changes to current practice need to be made.”

—Mark McGraw

Reference

Carstensen B, Read S, et al. Cancer incidence in persons with type 1 diabetes: a five-country study of 9,000 cancers in type 1 diabetic individuals. Diabetologia. 2016. doi:10.​1007/​s00125-016-3884-9