Clinical Outcomes of Intraductal Papillary Mucinous Neoplasms With Dilatation of the Main Pancreatic Duct

BACKGROUND & AIMS: Dilatation of the main pancreatic duct (MPD) has been a surgical indication for intraductal papillary mucinous neoplasms (IPMNs). Few studies have investigated long-term outcomes of IPMNs with MPD dilatation. METHODS: Among 3610 patients diagnosed with pancreatic cysts between 1994 and 2021, we identified 2829 IPMN patients, including 282 patients with MPD >5 mm, and examined short-term (& POUND;6 months) and long-term risks of pancreatic carcinoma. Utilizing competing risks proportional hazards models, we estimated subdistribution hazard ratios for incidence of pancreatic carci-noma with adjustment for potential confounders. RESULTS: In analyses of short-term outcomes of the 282 patients with MPD dilatation, 72 (26%) pa-tients were diagnosed with pancreatic carcinoma based on surgical or nonsurgical explora-tion. During long-term follow-up of 168 patients, we documented 24 (14%) patients diagnosed with pancreatic carcinoma (18 with IPMN-derived carcinoma and 6 with concomitant ductal adenocarcinoma). The patients with the MPD = 5-9.9 mm had cumulative incidence rates of pancreatic carcinoma diagnosis of 8.1% (95% confidence interval [CI], 4.3%-13.5%) and 10.0% (95% CI, 5.5%-15.9%) at 2 and 5 years, respectively; and the pa-tients with the MPD >10 mm had the corresponding rates of 16.0% (95% CI, 3.6-36.5%) and 33.3% (95% CI, 10.3%-58.8%). The multivariable subdistribution hazard ratios were 2.78 (95% CI, 1.57-4.90) and 7.00 (95% CI, 2.58-19.0) for the MPD = 5-9.9 mm and >10 mm (vs <5 mm), respectively. CONCLUSIONS: IPMNs with MPD dilatation at baseline were associated with higher prevalence and incidence of pancreatic carcinoma compared with IPMNs with no MPD dilatation.

Automated summary

This study investigated the long-term effects of dilation of the main pancreatic duct (MPD) on intraductal papillary mucinous neoplasms (IPMNs) and found that MPD dilation was associated with higher incidence and prevalence of pancreatic carcinoma.