What is the recommended frequency of colonoscopies for a patient with rectal cancer, status post low anterior resection, chemo-radiation with Xeloda (capecitabine), and loop transverse colostomy?

Colonoscopy Surveillance Schedule After Rectal Cancer Resection

For a patient with rectal cancer who underwent loop transverse colostomy, chemoradiation with Xeloda, and low anterior resection, colonoscopy surveillance should follow a 1-3-5 year schedule: first colonoscopy at 1 year after resection, then at 3 years if normal, and subsequently every 5 years if normal. 1

Initial Surveillance Timeline

• The patient should have undergone high-quality perioperative clearing colonoscopy either before or during the surgical procedures in 2018 1
• First surveillance colonoscopy should be performed 1 year after the low anterior resection (which would have been in October 2019) 1
• If the first surveillance colonoscopy was normal, the next colonoscopy should be performed 3 years later (approximately October 2022) 1
• If that examination was normal, the subsequent colonoscopy should be performed 5 years later (approximately October 2027) 1

Special Considerations for Rectal Cancer

• In addition to the standard colonoscopy surveillance, patients with rectal cancer who underwent low anterior resection should have periodic examination of the rectum to identify local recurrence 1
• These rectal examinations are typically performed at 3-6 month intervals for the first 2-3 years after surgery using rigid proctoscopy, flexible proctoscopy, or rectal endoscopic ultrasound 1
• Local recurrence rates for rectal cancer may be up to 10 times higher than for colon cancer, which justifies this additional surveillance 1
• These rectal examinations are independent of the colonoscopic examinations described above 1

Factors That May Modify the Surveillance Schedule

• The surveillance intervals may need to be shortened if any of the following are present:
  • Evidence of hereditary nonpolyposis colorectal cancer 1
  • Adenoma findings (based on histology, size, and number) that warrant earlier colonoscopy 1
• The quality of the colonoscopy examination is crucial - if bowel preparation was inadequate, the examination should be repeated before planning the long-term surveillance schedule 1

Rationale for This Surveillance Schedule

• The 1-year colonoscopy is critical as it has a high yield for detecting early second, apparently metachronous cancers 1
• However, research has shown that the actual detection rate of metachronous cancers at the 1-year mark is relatively low (1.3%), suggesting that the timing could potentially be extended in the future 2
• The 3-5 year subsequent intervals are based on the low incidence of metachronous lesions detected during follow-up 2
• Studies have shown that anastomotic recurrences are rare (0.7-8.7%), with most being detected during the first surveillance colonoscopy 3, 4, 2

Common Pitfalls to Avoid

• Skipping the 1-year colonoscopy, which is crucial for detecting early recurrences and metachronous lesions 1
• Failing to perform adequate perioperative clearing colonoscopy, which is essential for proper surveillance 1
• Not performing the additional rectal examinations for local recurrence detection, which are particularly important after low anterior resection for rectal cancer 1
• Extending surveillance intervals without proper documentation of normal findings in previous examinations 1