New-onset type 2 diabetes mellitus--A high-risk group suitable for the screening of pancreatic cancer?

Background: Type 2 diabetes mellitus is widely considered to be associated with pancreatic cancer.

Objective: To determine the incidence of pancreatic cancer in new-onset type 2 diabetic patients by measuring the serum level of CA 19-9 and performing abdominal ultrasonography (US).

Patients and methods: Consecutive type 2 diabetic patients in whom diabetes was diagnosed within 36 months were included in this prospective study. Serum CA 19-9 measurement and US were performed in all patients. If any of two was positive, abdominal computer tomography (CT) was carried out. Endoscopic ultrasound-guided fine needle aspiration or direct surgical referral was performed on patients with CT-identified lesions.

Results: A total of 115 patients were enrolled. CA 19-9 was elevated in 10 patients but pancreatic cancer diagnosed in neither of them. Pancreatic cancer was revealed by morphological means in three patients without elevated CA 19-9 level. The sensitivity, specificity, positive-, negative predictive values and validity were 0%, 90.4%, 0%, 97.9% and 87.9% for CA 19-9, 66.7%, 100%, 100%, 99% and 99% for US, respectively. The value of the Standardized Incidence Ratio for pancreatic cancer in new-onset type-2 diabetic patients was 198.6 (95% CI = 6.25-46.9).

Conclusions: The prevalence of pancreatic cancer in patients with new-onset type-2 diabetes is significantly higher than that in the general population and screening is beneficial for detecting PaC in this patient population. CA 19-9 and US is not reliable screening modality for pancreatic cancer screening in this population.