Genotypical analysis of gastrointestinal stromal tumors using next-generation sequencing

Background:To study the prevalence of genetic mutations in patients with gastrointestinal stromal tumors (GIST) using next-generation sequencing at a tertiary care center in northern India. Methods:We performed genotypic analysis of histologically and immunohistochemically diagnosed GIST using Ion AmpliSeq Cancer Hotspot Panel v2 to identify mutations on resected biopsy samples. Results:In our cohort of 41 patients, we observed a variety of genetic mutations. The corresponding prevalence for those mutations was Tumour Protein 53 (TP53) 90%, KIT Protooncogene receptor tyrosine kinase (KIT) 88%, Platelet Derived Growth Factor Receptor (PDGFRA) 78%, HRas Proto-oncogene (HRAS) 61%, Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) 56%, Kristen rat sarcoma viral oncogene homolog (KRAS) 54%, NRas Proconcogene GTPase (NRAS) 20%, Cyclin-dependent kinase inhibitor 2A (CDKN2A) 15%, and B-Raf proto-oncogene (BRAF) 7%. Conclusion:GISTs host a variety of mutations that need to be further investigated for their interplay and overall effect on the Indian population so that we can tailor treatment for better prognosis. The incidence of GIST is rising worldwide. Advances in technology have made tailored theranostics a possibility in managing GIST. Detailed genetic presentation of GIST is still unclear. Next-generation sequencing has provided us with an excellent tool to prospectively analyze the genetic makeup of GIST and most of the tumors. The present study opens up a huge possibility for using molecular makers for risk stratification of GIST and for theranostics of such tumors.