Usefulness of CA 19–9 for pancreatic cancer screening in patients with new-onset diabetes

Background: Generally, carbohydrate antigen 19–9 (CA 19–9) is not useful for screening pancreatic cancer in the asymptomatic general population. This study aimed to evaluate the utility of CA 19–9 level as a screening indicator of pancreatic cancer in asymptomatic patients with new-onset diabetes. Methods: We retrospectively reviewed the medical records of patients who visited our health promotion center for health check-ups without cancer related symptoms from January 2005 to January 2014, and were newly diagnosed with diabetes mellitus (DM) within 2 years before their visit. Results: Of the 5111 asymptomatic patients with new-onset DM (<2 years) selected for analyses, 87 (1.7%) eventually developed pancreatic cancer after the health check-up. In the subgroup of 322 patients with high total bilirubin levels (>1.7 mg/dL) at the screening time, 42 (73.7%) of 57 patients with high CA 19–9 levels (>37 IU/mL) had been diagnosed as pancreatic cancer during follow-up period and 12 (4.5%) of 265 patients with normal CA 19–9 levels had finally developed pancreatic cancer (OR = 16.3). In the subgroup of 4789 patients with normal bilirubin levels, pancreatic cancer had been detected in 20 (3.8%) of 522 patients with high CA 19–9 level, while only 13 (0.3%) in 4267 patients with normal CA 19–9 levels (OR = 12.6), respectively. Conclusion: CA 19–9 levels after a diagnosis of new-onset DM could be a useful biomarker of pancreatic cancer, especially in patients with high serum bilirubin.