Prevalence of new onset diabetes mellitus among patients with pancreatic ductal adenocarcinoma: a population-based study

Background: Pancreatic ductal adenocarcinoma (PDAC) has remained one of the most serious malignancies and is still a leading cause of cancer-related deaths worldwide. Great attention has been paid to the relationship between diabetes mellitus and PDAC. The aim of our study was to analyse the mutual association of PDAC and diabetes mellitus in the entire population of the Czech Republic within a 5-year period. Methods: The incidence of PDAC in 2018-2022 was estimated based on the individual population data from the Czech National Cancer Registry. Another data source, the National Registry of Reimbursed Health Services that collects data from health insurance companies, was used to identify individuals recently diagnosed with diabetes mellitus. For the purpose of this study, diagnosis of new-onset of diabetes mellitus was defined as the time of the first prescription of any antidiabetic drug or another related health care service. Subsequently, patients diagnosed with PDAC in 2022 were followed retrospectively to see if they had been diagnosed with diabetes mellitus in the last five years before diagnosis of pancreatic cancer. Results: In 2022, 2,189 patients aged 60 years or older were diagnosed with pancreatic cancer. New-onset diabetes was observed in 17.4% within five years prior to diagnosis, with the highest occurrence (12.4%) within the last three years. Among patients aged 60-74 years, the respective proportions were 14.4% within three years and 5.7% four to five years prior to pancreatic cancer diagnosis. Conclusion: The incidence of pancreatic cancer in the Czech Republic is among the highest in Europe. One-fifth of PDAC cases are diagnosed following new-onset diabetes mellitus in patients over sixty. Unintended significant weight loss combined with new-onset diabetes thus must not be overlooked, as these can be early signs of PDAC. An individualised diagnostic work-up should follow without any unnecessary delay.