1. How to classify the risk of gastrointestinal stromal tumors.
In general, the higher the risk, the higher the risk of recurrence and metastasis of GIST. For surgically resected GIST tissue specimens, risk classification should be carried out in order to guide follow-up treatment, including whether postoperative imatinib targeted therapy and treatment time.2. Gene detection of gastrointestinal stromal tumors.At present, the gene detection of GIST is mainly to analyze the mutations in exons 9, 11, 13 and 17 of KIT gene and exon 12 and 18 of PDGFRA gene. KIT gene mutations (accounting for 80% of GIST) mainly occurred in exon 11 (65%), followed by exon 9 (10%), and occasional mutations in exons 13 and 17. PDGFRA gene mutations (accounting for about 10% of GIST) mainly occurred in exon 18 of D842V and were resistant to imatinib, a first-line tyrosine kinase inhibitor. PDGFRA gene mutations often occur in gastric GIST, with the characteristics of epithelioid tumor and showing inertia. Gene detection has diagnostic value in CD117-negative GIST (see pathological diagnosis) and can be used to predict imatinib response in GIST. For example, the GIST of D842V should not be treated with imatinib, while the mutation in exon 9 of KIT gene should increase the dose of imatinib.
