May 4, 2020
Cathy Eng, MD, FACP, FASCO


Case: A 68-Year-Old Woman With Metastatic NTRK Fusion-Positive Colon Cancer

Initial presentation

  • A 68-year-old woman presented with a 3-month history of intermittent abdominal pain, and alternating constipation/diarrhea
  • PMH/SH: hypertension and hypercholesterolemia, medically managed; colonoscopy at age 50 was unremarkable; never smoker; no family history of cancer
  • PE: abdomen tender on deep palpation in the right lower quadrant

Clinical workup

  • Labs: Hb 11.9, Hct 32%, MCV 75 fL, CEA 12.8 ng/mL
  • Chest/abdominal/pelvic CT showed a 5-cm right sided bowl mass and multiple hepatic lesions, and regional lymphadenopathy
  • Colonoscopy revealed a 5-cm mass in the ascending colon, biopsy was taken
  • Pathology: grade 3 poorly differentiated adenocarcinoma, with invasion of the submucosa
  • Biomarkers: KRAS-wt, NRAS-wt, BRAF-, NTRK+; MSI-H
  • Stage TXNXM1; ECOG PS 1