Abstract
Background: Strict follow-up is recommended for branch-duct intraductal papillary mucinous neoplasms (BD-IPMN) to avoid missing the development of high-risk stigmata (HRS) at a premalignant stage. This study aimed to identify the risk factors associated with the development of HRS during follow-up.Methods: We performed a retrospective analysis of 283 patients with BD-IPMN, treated at the Okayama University Hospital in Japan between January 2009 and December 2016. Only patients with imaging studies indicative of classical features of BD-IPMN without HRS and followed for >1 year were included in the study. We performed radiological follow-up every 6 months and collected patients’ demographic data, cyst characteristics, and clinical outcomes. Cyst size was recorded at the initial and final imaging studies and growth rate was calculated. The primary outcome was to evaluate the risk factors for development of HRS in patients with BD-IPMN without HRS at the initial diagnosis.Results: Patients with BD-IPMN had a median follow-up of 53.3 months. Based on image analyses, a mean cysts size were initially 18.0 mm and their final size was 20.4 mm, and the mean annual cyst growth was 0.57 mm. Among them, 10 patients (3.5%) developed HRS after a median surveillance period of 55.8 months. Main pancreatic duct (MPD) size (5-9 mm) and cyst growth rate (>2.5 mm/year) were, both, independent risk factors for the development of HRS (odds ratio, 14.2; 95% CI, 3.1-65.2, P = .0006, and odds ratio, 6.1; 95% CI 1.5-25.5, P = .014). Considering the number of worrisome features (WFs), the rate of HRS development was not a WF: 2.0% (4/199), a single WF: 1.6% (1/62), multiple WFs: 22.7% (5/22), and significantly higher in multiple WFs (95% CI: 4.0–57.1; p=.0003).Conclusions: MPD dilation, rapid cyst growth, and multiple WFs were significant risk factors for the development of HRS. In the presence of such features, it is necessary to closely follow the development of HRS and avoid missing the best opportunity for surgical intervention.
Follow up of main duct intraductal papillary mucinous neoplasms of the pancreas
