A 34-year-old woman has gastric bleeding from a submucosal mass. Biopsy shows spindle cells positive for CD117 (c-KIT). After complete resection with clear margins, which targeted agent is indicated for a high-risk tumour?
- A Trastuzumab
- B Imatinib mesylate ✓
- C Sorafenib
- D Erlotinib
Correct answer: B. Imatinib mesylate
Explanation
Gastrointestinal stromal tumours arise from interstitial cells of Cajal and carry activating mutations of KIT (CD117) in about 80 percent of cases, or PDGFRA in a minority. Imatinib, a tyrosine kinase inhibitor of KIT and PDGFR, is standard adjuvant therapy for high-risk resected GISTs and first-line therapy for metastatic disease. Trastuzumab targets HER2 in gastric and breast cancers, erlotinib targets EGFR, and sorafenib is used in hepatocellular and renal carcinoma.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.