June 22, 2020
Margaret von Mehren, MD


Case: A 68-Year-Old Man With Gastrointestinal Stromal Tumor

Initial presentation

  • A 68-year-old man complains of a 5-month history early satiety and vague abdominal pain
  • PMH: hypertension, medically controlled; colonoscopy at age 55 unremarkable; no family history of cancer
  • PE: diffuse abdominal pain on palpation; otherwise unremarkable

Clinical workup

  • Labs: Hb 10.1 g/dL, plt 100 x 109/L; other lab values WNL
  • Endoscopy: showeda submucosal ~ 5 cm mass with ulceration
  • EUS-FNA biopsy: irregular borders on extraluminal surfaces of the stomach with evidence of heterogeneous echogenicity
  • Biopsy showed gastrointestinal tumor with mitotic activity showed >5 mitoses/50 HPFs
  • Abdominal/pelvic CT confirmed a 5.4 cm lesion in the body of the stomach
  • MRI showed evidence of peritoneal metastases
  • IHC and genetic mutational analysis: KIT exon 11 mutation
  • ECOG 0

Treatment

  • He was started on imatinib 400 mg PO qDay, continued for 26 months until he complained of increased abdominal pain and decreased appetite
    • ECOG 1; Imatinib was discontinued due to progressive disease
  • Treatment with sunitinib 50 mg PO qDay for 4 weeks, with a 2-week drug-free interval was started
    • Treatment was well tolerated for 9 cycles when he developed an altered sense of taste, occasional vomiting and diarrhea; sunitinib was discontinued
  • Regorafenib 160 mg (four 40 mg tablets) PO qDay for the first 21 days of each 28-day cycle was started and tolerated except for hand-foot syndrome
    • Regorafenib was discontinued on progression of disease
  • The patient was started on ripretinib 150 mg PO qDay