Main pancreatic duct dilation greater than 6 mm is associated with an increased risk of high-grade dysplasia and cancer in IPMN patients.

Introduction: IPMNs, considered precursor lesions of pancreatic adenocarcinoma (PDAC), might display histological alteration varying from low-grade dysplasia (LGD) to cancer. Nevertheless, the prevalence of PDAC is far below the prevalence of IPMN; therefore, not all of these precursor lesions finally progress to cancer. Preoperative features consistent with and finding at final histology of high-grade dysplasia (HGD) or cancer are currently lacking. The aim of this study is to correlate the presence of preoperative clinical features with the finding of advance lesions at final histology.

Methods: This is retrospective cohort analysis of patients who underwent surgery for histologically confirmed IPMNs at Karolinska University Hospital, from 2008 to 2015.

Results: MPD 6-9.9 mm and ≥ 10 mm were associated with an increased risk of HGD/cancer (respectively, OR 2.92, CI 1.38-6.20, p = 0.005 and OR 2.65, CI 1.12-6.25, p = 0.02). Preoperative high CA19.9 and jaundice were both associated with a higher risk of HGD/cancer at final histology (respectively, OR 4.15, CI 1.90-9.05, p = 0.0003 and OR 15.36, CI 1.94-121.22, p = 0.009). At sex- and age-adjusted multivariable logistic regression analysis, MPD between 6 and 9.9 mm (OR 2.64, CI 1.15-6.06, p = 0.02), jaundice (OR 12.43, CI 1.44-106.93, p = 0.02), and elevated CA19.9 (OR 3.71, CI 1.63-8.46, p = 0.001) remained associated with the occurrence of HGD/cancer.

Discussion: The presence of MPD dilation ≥ 6 mm, jaundice, and elevated CA19.9 in IPMN patients are consistent with the finding for HGD/cancer at final histology, thus representing possible markers of advanced lesions suitable for earlier or preventive curative surgical treatment.