February 20, 2019

Case: A 38-year Old Woman WithKRAS-Mutated mCRC

Initial presentation

  • A 38-year old woman was referred to gastroenterology after experiencing several bouts of bloody diarrhea
  • PMH: unremarkable
  • PE: unremarkable

Clinical workup

  • Colonoscopy: suspicious sigmoid mass, partial obstruction
  • Biopsy: poorly differentiated adenocarcinoma
  • Imaging: CT scan of the chest/abdomen/pelvis revealed multiple small bilateral liver metastases
  • Molecular testing on tissue biopsy:
    • Positive forKRASexon 2 codon 12 mutation
    • Negative forNRAS,BRAF
    • Microsatellite-stable
  • Diagnosis: stage IV colorectal cancer
  • ECOG PS 0


  • She underwent laparoscopic sigmoid resection
  • She was initiated on treatment with FOLFOX + bevacizumab; well-tolerated
  • Follow-up imaging at 3 and 6 months showed a partial response