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

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.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.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.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.