Diabetes spells increased cancer risk

People with diabetes are at heightened risk of cancer, with the risk starting to increase even before the diagnosis of diabetes and peaking in the year after, according to a study.

The retrospective study included of 3 681 774 individuals, of which 86,537 had diabetes and were included in the case group (average age 61.4 years, 46.7 percent male) and the remaining 3,595,237 without diabetes comprised the control group (average age 58.0 years, 45.6 percent male).

Researchers conducted univariate and multivariate Cox regression analyses to explore the potential relationship between diabetes status and cancer diagnosis.

During the observation period, cancer diagnosis was documented in 10.1 percent of participants in the case group and in 8.6 percent of those in the control group.

Diabetes was consistently associated with a higher risk of incident cancer for each of the following sites: pancreas (hazard ratio [HR], 2.294, 99 percent confidence interval [CI], 2.099–2.507), liver (HR, 1.830, 99 percent CI, 1.631–2.054), breast cancer (HR, 1.137, 99 percent CI, 1.055–1.227), and prostate (HR, 1.171, 99 percent CI, 1.071–1.280).

The difference in cancer rate between the two groups was driven by the more frequent cancer diagnosis in the younger age group (40–54 years: 5.4 percent vs 4.4 percent; 70–89 years: 12.7 percent vs controls 12.4 percent). Analysis stratified by sex yielded no consistent results.

Of note, cancer incidence started to increase before the diagnosis of diabetes and peaked in the year after.  

The findings highlight the importance of revisiting screening activities in this population, with diabetes guidelines complemented with recommendations on cancer prevention.