Intraductal Papillary Mucinous Neoplasms Arise From Multiple Independent Clones, Each With Distinct Mutations

Gastroenterology. 2019 Oct;157(4):1123-1137.e22. doi: 10.1053/j.gastro.2019.06.001. Epub 2019 Jun 5.


Background & aims: Intraductal papillary mucinous neoplasms (IPMNs) are lesions that can progress to invasive pancreatic cancer and constitute an important system for studies of pancreatic tumorigenesis. We performed comprehensive genomic analyses of entire IPMNs to determine the diversity of somatic mutations in genes that promote tumorigenesis.

Methods: We microdissected neoplastic tissues from 6-24 regions each of 20 resected IPMNs, resulting in 227 neoplastic samples that were analyzed by capture-based targeted sequencing. Somatic mutations in genes associated with pancreatic tumorigenesis were assessed across entire IPMN lesions, and the resulting data were supported by evolutionary modeling, whole-exome sequencing, and in situ detection of mutations.

Results: We found a high prevalence of heterogeneity among mutations in IPMNs. Heterogeneity in mutations in KRAS and GNAS was significantly more prevalent in IPMNs with low-grade dysplasia than in IPMNs with high-grade dysplasia (P < .02). Whole-exome sequencing confirmed that IPMNs contained multiple independent clones, each with distinct mutations, as originally indicated by targeted sequencing and evolutionary modeling. We also found evidence for convergent evolution of mutations in RNF43 and TP53, which are acquired during later stages of tumorigenesis.

Conclusions: In an analysis of the heterogeneity of mutations throughout IPMNs, we found that early-stage IPMNs contain multiple independent clones, each with distinct mutations, indicating their polyclonal origin. These findings challenge the model in which pancreatic neoplasms arise from a single clone. Increasing our understanding of the mechanisms of IPMN polyclonality could lead to strategies to identify patients at increased risk for pancreatic cancer.

Keywords: PDAC; carcinogenesis; driver gene; oncogene.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Biomarkers, Tumor / genetics*
  • Cell Transformation, Neoplastic / genetics*
  • Cell Transformation, Neoplastic / pathology
  • Chromogranins / genetics
  • Clonal Evolution
  • DNA Mutational Analysis
  • DNA-Binding Proteins / genetics
  • Evolution, Molecular
  • Female
  • GTP-Binding Protein alpha Subunits, Gs / genetics
  • Genetic Predisposition to Disease
  • Humans
  • Male
  • Middle Aged
  • Mutation Rate
  • Mutation*
  • Neoplasm Staging
  • Oncogene Proteins / genetics
  • Pancreatic Intraductal Neoplasms / genetics*
  • Pancreatic Intraductal Neoplasms / pathology
  • Pancreatic Neoplasms / genetics*
  • Pancreatic Neoplasms / pathology
  • Phenotype
  • Proto-Oncogene Proteins p21(ras) / genetics
  • Retrospective Studies
  • Ubiquitin-Protein Ligases


  • Biomarkers, Tumor
  • Chromogranins
  • DNA-Binding Proteins
  • KRAS protein, human
  • Oncogene Proteins
  • RNF43 protein, human
  • Ubiquitin-Protein Ligases
  • GNAS protein, human
  • GTP-Binding Protein alpha Subunits, Gs
  • Proto-Oncogene Proteins p21(ras)