MKSAP Quiz: ulcerative colitis
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A 27-year-old woman with an 8-year history of ulcerative colitis is evaluated during a follow-up examination. The initial colonoscopy after diagnosis showed pancolitis. She has been treated with mesalamine since diagnosis and has had episodes of bloody diarrhea two or three times a year but has otherwise done well. Her most recent colonoscopy 1 year ago when she had increased diarrhea and bleeding showed no progression of disease. Since then she has been clinically stable. The patient's medical history includes nephrolithiasis, and her only medications are mesalamine, 2.4 g/d, and a multivitamin. There is no family history of inflammatory bowel disease or colorectal cancer.
On physical examination, vital signs are normal; BMI is 20.5. There is mild abdominal tenderness in the right lower quadrant without rebound or guarding. The rest of the physical examination is normal. Laboratory studies reveal a normal complete blood count, including leukocyte differential, and a serum C-reactive protein level of 0.8 mg/dL (8 mg/L).
Which of the following is the most appropriate management of this patient's risk for colorectal cancer?
A. Annual capsule endoscopy
B. Annual flexible sigmoidoscopy
C. Colonoscopy now and annually thereafter
D. Increasing the dose of mesalamine to 3.6 g/d
MKSAP Answer and Critique
The correct answer is C) Colonoscopy now and annually thereafter. This item is available to MKSAP 15 subscribers as item 4 in the Gastroenterology and Hepatology module.
This patient has pancolitis of 8 years' duration. The inflammation involves the ileum and proximal colon. The colon cancer risk in patients with ulcerative colitis or Crohn disease reaches a significant level after 8 years of inflammation; the annual cancer risk is estimated to be 1% to 2% per year after 8 years. The cancer risk is slightly delayed for patients with inflammation limited to the distal colon. The recommendation is to initiate a surveillance program with colonoscopy 8 years after onset of her disease, with follow-up colonoscopy every 1 to 2 years thereafter. Biopsies are performed in four-quadrant fashion throughout the entire colon.
The patient's disease is reasonably well controlled on her current dose of mesalamine, and treatment with mesalamine does not in itself prevent colon cancer. There is no recommendation for standard screening for small-bowel carcinoma in the setting of ulcerative colitis or Crohn disease, and therefore, capsule endoscopy is not indicated. Flexible sigmoidoscopy would not reach the at-risk colonic mucosa in the proximal colon beyond the reach of the sigmoidoscope.
Key Point
- Patients with inflammatory bowel disease should initiate screening for colorectal cancer after 8 years of duration of disease.