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Updated: Jun 23, 2026

Comparative Lesions Analysis Through a Targeted Sequencing Approach
08:16

Comparative Lesions Analysis Through a Targeted Sequencing Approach

Published on: November 5, 2019

Molecular analysis of PIK3CA, BRAF, and RAS oncogenes in periampullary and ampullary adenomas and carcinomas

Frank Schönleben1, Wanglong Qiu, John D Allendorf

  • 1Department of Otolaryngology/Head and Neck Surgery, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.

Journal of Gastrointestinal Surgery : Official Journal of the Society for Surgery of the Alimentary Tract
|May 15, 2009
PubMed
Abstract

Insights

KRAS and BRAF mutations drive periampullary and ampullary tumor development, while NRAS, HRAS, and PIK3CA do not. BRAF mutations are more common in periampullary neoplasms.

Area of Science:

  • Oncology
  • Molecular Biology
  • Gastroenterology

Background:

  • KRAS mutations are implicated in periampullary and ampullary tumors.
  • The roles of NRAS, HRAS, BRAF, and PIK3CA mutations in these neoplasms were previously unknown.
  • Oncogenic BRAF contributes to pancreatic ductal adenocarcinoma and intraductal papillary mucinous neoplasms/carcinomas (IPMN/IPMC), while PIK3CA mutations are found in IPMN/IPMC.

Purpose of the Study:

  • To investigate the potential involvement of BRAF and PIK3CA in the development of ampullary and periampullary adenomas and carcinomas.
  • To analyze the mutation status of KRAS, NRAS, HRAS, BRAF, and PIK3CA in these tumor types.

Main Methods:

  • Direct genomic sequencing was used to examine specific exons of KRAS, NRAS, HRAS, BRAF, and PIK3CA.
  • The study analyzed mutations in seven adenomas, seven adenomas with carcinoma in situ, and 21 adenocarcinomas from the periampullary duodenal region and ampulla of Vater.

Main Results:

  • KRAS mutations were identified in 28.6% of tumors (10/35).
  • BRAF mutations were found in 6% of tumors (2/35), including a V600E hot spot mutation.
  • BRAF mutations were more prevalent in periampullary tumors compared to ampullary tumors.

Conclusions:

  • KRAS and BRAF oncogenic mutations contribute to the tumorigenesis of periampullary and ampullary tumors.
  • NRAS, HRAS, and PIK3CA mutations do not appear to play a significant role in the development of these neoplasms.
  • BRAF mutations show a higher frequency in periampullary neoplasms than in ampullary neoplasms.

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