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Updated: Mar 8, 2026
Molecular and Immunologic Techniques in a Genetically Engineered Mouse Model of Gastrointestinal Stromal Tumor
Published on: May 2, 2022
Somatic mutational spectrum analysis in a prospective series of 104 gastrointestinal stromal tumors
David Guenat1, Olivier Deroo1, Sandrine Magnin1
1CHRU Besançon, Besançon, France.
Abstract:
Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors distinguished by driver mutations in proto-oncogenes KIT or PDGFRA in 85-90% of cases. These mutations have been linked to the response to imatinib, a multikinase inhibitor, and have independent prognostic impact. Here, we describe the prospective study of the molecular characteristics of 104 GISTs from French adult patients analyzed routinely through the National Hospital Program of Molecular Cancer Diagnosis. All patients with GISTs diagnosed at the University Hospital of Besançon between August 2005 and October 2014 were prospectively included in the present study. KIT, PDGFRA and KRAS-codons 12 and 13 as well as BRAF codon 600 mutations were analyzed by Sanger sequencing or SNaPshot. KIT and PDGFRA mutations were detected in 71.2 and 19.2% of the cases, respectively. A total of 43 different mutations were detected of which 13 had never been described. As expected, KIT exon 9 and PDGFRA exon 18 mutations were associated with small bowel and gastric localizations respectively. No mutation was found in KRAS and BRAF. Molecular studies are critical to improve the management of GISTs. Our study enhances the current knowledge by describing 13 new mutations in KIT. A common molecular pattern in all KIT exon 11 substitutions is also described for the first time in this study but its significance remains unknown since genetic and environmental risk factors favoring the development of GISTs such as DNA repair defects and exposure to carcinogens are not currently known.
Insights
This study identified 13 novel KIT mutations in gastrointestinal stromal tumors (GISTs), enhancing molecular understanding. These findings are crucial for improving GIST diagnosis and treatment strategies.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- Gastrointestinal stromal tumors (GISTs) are mesenchymal neoplasms frequently driven by KIT or PDGFRA proto-oncogene mutations.
- These mutations influence patient response to imatinib therapy and impact prognosis.
- Understanding GIST molecular landscape is vital for clinical management.
Purpose of the Study:
- To prospectively analyze the molecular characteristics of 104 GISTs in adult French patients.
- To identify novel mutations and describe common molecular patterns in GISTs.
- To contribute to improved diagnostic and therapeutic approaches for GIST patients.
Main Methods:
- Prospective analysis of 104 GISTs diagnosed at University Hospital of Besançon (2005-2014).
- Analysis of KIT, PDGFRA, KRAS (codons 12/13), and BRAF (codon 600) mutations using Sanger sequencing or SNaPshot.
- Identification of mutation types, frequencies, and associations with tumor location.
Main Results:
- KIT and PDGFRA mutations were found in 71.2% and 19.2% of GISTs, respectively.
- A total of 43 distinct mutations were identified, including 13 previously undescribed KIT mutations.
- KIT exon 9 and PDGFRA exon 18 mutations correlated with small bowel and gastric GISTs, respectively; no KRAS or BRAF mutations were detected.
Conclusions:
- Molecular profiling of GISTs is essential for effective patient management.
- The discovery of 13 new KIT mutations expands the known GIST mutational spectrum.
- A novel common molecular pattern in KIT exon 11 substitutions was observed, though its clinical significance requires further investigation.
