2810 Endoscopic Ultrasound in Diabetics: Is There a Protective Role of Metformin Therapy for Pancreatic Ductal Adenocarcinoma?

Abstract

INTRODUCTION: The relationship between diabetes mellitus (DM) and pancreatic ductal adenocarcinoma (PDAC) is a field of immense interest. Studies have proposed that metformin therapy (MT) could play a protective role in risk reduction for PDAC; however, the prevalence of pancreatic structural abnormalities in patients on MT is unknown. We aimed to identify the prevalence and distribution of pancreatic parenchymal and ductal changes during endoscopic ultrasound (EUS) of diabetic patients on MT, compared to patients non-MT. METHODS: We performed a retrospective chart review of diabetic patients who underwent EUS at the University of Miami Health System between 2010-2018. Patients with known history of chronic pancreatitis (CP), pancreatic mass/PDAC or pancreatic surgery were excluded. RESULTS: Seventy-eight patients were identified (mean age = 65 ± 13.6 years; M:F = 31:47): 18 (23%) African-American, 17 (22%) Caucasian and 43 (55%) Hispanic. Mean BMI was 31.55 ± 9.8. Four patients (5%) had DM type 1 and 74 (95%) had type 2, with mean hemoglobin A1c of 6.45 ± 2%. Diabetic complications were seen in 44 patients (56.4%): nephropathy = 25, neuropathy = 26 and retinopathy = 6. Forty-four (56.7%) patients were on MT and 34 (43.5%) patients were on either insulin (n = 20) or insulin secretagogue (n = 14), defined as non-MT group (Table 1) Indications for EUS included abdominal pain (24), submucosal esophageal (2), gastric (11) or duodenal (3) lesion, common biliary narrowing or dilation (18), abnormal hepatic panel (3), lymphadenopathy on imaging (5), suspected choledocholithiasis (3), jaundice (2), and elevated CA-19-9 (2). Parenchymal or ductal endosonographic findings were present in 34% (n = 15) of the patients on MT versus 53% (18) of patients non-MT (Table 2). Among the 44 patients on MT, 2 patients met criteria for chronic pancreatitis (CP), 1 was indeterminate and 41 (93.2%) were classified as normal pancreas, according to the Rosemont classification. In non-MT patients, 32 (94.11%) were classified as having normal pancreas, 2 were indeterminate and no patients met criteria for CP. Following EUS examination, PDAC was diagnosed in 1 (2.2%) patient in MT group, versus 3 patients (8.8%) in the non-MT group. CONCLUSION: Pancreatic structural abnormalities occurred equally in diabetic patients in MT (6.8%) versus non-MT (5.8%) groups (P = ns). Higher number of PDAC were diagnosed in non-MT group; however, whether or not this finding could explain the proposed protective role of MT on the risk of developing PDAC is yet unclear.