Natural history of pancreatic cystic lesions: A multicenter prospective observational study for evaluating the risk of pancreatic cancer

J Gastroenterol Hepatol. 2018 Jan;33(1):320-328. doi: 10.1111/jgh.13967.

Abstract

Background and aim: The aim of this study is to elucidate the natural history of pancreatic cystic lesions (PCLs), including branch duct-type intraductal papillary mucinous neoplasm (BD-IPMN), via midterm follow-up analysis of a multicenter prospective observational study (NSPINAL study).

Methods: From July 2011 to October 2016, 881 patients with PCLs were enrolled in NSPINAL study, and 664 patients with > 12 months of follow up were analyzed. Every patient was asymptomatic, and endoscopic ultrasound was performed at the initial diagnosis to exclude high-risk individuals. Follow up included endoscopic ultrasound, computed tomography, or magnetic resonance imaging at least once a year. Serial morphological changes and the pancreatic cancer (PC) incidence, including malignant progression of PCLs, were evaluated.

Results: The 664 patients (358 men) were followed for a median of 33.5 months (interquartile range 29). The cyst and main pancreatic duct sizes were 16.6 ± 9.3 and 2.3 ± 1.0 mm, respectively. Morphologically, 518 cases were multilocular, 137 were unilocular, and 9 had a honeycomb pattern; 269 cases involved multifocal lesions. Ninety-six patients (14.5%) showed worsening progression on imaging. There were two resectable and four unresectable cases of pancreatic ductal adenocarcinoma and three cases of malignant BD-IPMN. The 3-year risk of developing PC was 1.2%. The standardized incidence ratio for PC among PCLs was 10.0 (95% confidence interval 3.5-16.5), and the standardized incidence ratio among BD-IPMN was 16.6 (95% confidence interval 5.1-28.1). Multivariate analysis showed that development of symptoms and worsening progression were significant predictors of PC.

Conclusions: Malignant progression of PCLs, including PC development, is not uncommon. Patients with PCLs should be carefully monitored to detect pancreatic ductal adenocarcinoma at early stages.

Keywords: malignant alteration; natural history; pancreatic cancer; pancreatic cysts.

Publication types

  • Multicenter Study
  • Observational Study

MeSH terms

  • Aged
  • Carcinoma, Pancreatic Ductal / diagnostic imaging*
  • Carcinoma, Pancreatic Ductal / etiology*
  • Carcinoma, Pancreatic Ductal / pathology
  • Diagnostic Imaging
  • Disease Progression
  • Early Detection of Cancer
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Pancreatic Cyst / complications*
  • Pancreatic Cyst / diagnostic imaging*
  • Pancreatic Cyst / pathology
  • Pancreatic Neoplasms / diagnostic imaging*
  • Pancreatic Neoplasms / etiology*
  • Pancreatic Neoplasms / pathology
  • Prospective Studies
  • Risk
  • Risk Assessment*
  • Time Factors