Chapter 11: A bunged up copper

A 45-year-old policewoman attended the emergency department with abdominal pain, swelling and constipation.

• 1. What does the abdominal X-ray show?

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  Correct answer:
  
  She was seen by a surgical registrar who immediately sent her for a CT scan.

• 2. What does the abdominal CT scan show?

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  Correct answer:
  CT scan confirmed dilation of the caecum (10 cm) and colon (7 cm) down to the sigmoid colon. The risk of bowel perforation due to obstruction is significant when the diameter of the small bowel exceeds 3 cm, the colon exceeds 6 cm or the caecum exceeds 9 cm.
  

In view of the risk of perforation a colonic stent was placed endoscopically.

Biopsy performed at the time of stenting revealed adenocarcinoma of the distal descending colon. The tumour was poorly differentiated and molecular analysis revealed a mutation of codon 12 exon 1 of K-Ras gene. Staging investigations confirmed stage IV disease with multiple pulmonary metastases that were identified on her admission plain chest X-ray.

• 3. What features would suggest that she had a hereditary colorectal cancer predisposition?

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  • Early age of cancer diagnosis (usually <40 years in this context)
  • Presence of multiple colonic polyps (>10)
  • Synchronous or metachronous cancers (either colorectal or other associated sites depending on the syndrome)
  • Positive family historyive chemotherapy

Metachronous cancers are two separate cancers that occur consecutively whilst synchronous cancers are two separate cancers that are diagnosed at the same time.

• 4. What dietary factors influence the risk of colon cancer?

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  • Red meat consumption increases the risk
  • Processed meat consumption increases the risk
  • Cereal fibre consumption reduces the risk
  • Vegetable fibre consumption reduces the risk
  • Dairy product consumption reduces the risk

Colorectal cancer also occurs more frequently in patients with inflammatory bowel disease. The overall prevalence of colon cancer in patients with IBD is about 4%. These tumours generally occur at younger ages and there is an increased frequency of multiple primaries (synchronous or metachronous).

• 5. What factors are associated with colon cancer development in patients with inflammatory bowel disease?

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  Correct answer:
  Duration of colitis (risk in UC patients is 2.5% after 20 years, 7.5% after 30 years and 10% after 40 years)<AU: Please expand “UC” and “IBD” if deemed necessary.> Extent of colonic involvement by IBD (proctitis risk<left-sided colitis risk<pancolitis risk) Family history of colorectal cancer