What is the recommended surveillance interval for a 60-year-old woman with a strong family history of colorectal cancer (father diagnosed at age 45, brother at age 48) after removal of a 12-mm tubular adenoma with low-grade dysplasia?

Surveillance Recommendation for Patient with 12-mm Tubular Adenoma and Strong Family History of Colorectal Cancer

The most appropriate surveillance recommendation for this 60-year-old woman with a 12-mm tubular adenoma with low-grade dysplasia and strong family history of colorectal cancer is a follow-up colonoscopy in 3 years. 1

Rationale for 3-Year Surveillance Interval

Risk Stratification Based on Adenoma Characteristics

The patient has two significant risk factors that determine her surveillance interval:

1. Adenoma Size ≥ 1 cm: The patient's 12-mm tubular adenoma exceeds the 1 cm threshold that classifies it as a high-risk finding, regardless of histology 1

2. Family History: The patient has a strong family history of colorectal cancer with first-degree relatives diagnosed at young ages (father at 45, brother at 48) 1

According to the US Multi-Society Task Force on Colorectal Cancer and American Cancer Society guidelines, patients with any adenoma ≥ 1 cm should have their next follow-up colonoscopy in 3 years, provided the adenoma was completely removed and not resected piecemeal 1.

Impact of Family History

While the guidelines primarily stratify risk based on polyp characteristics, they also note that family history should be considered when determining surveillance intervals, especially when it suggests hereditary nonpolyposis colorectal cancer (HNPCC) 1. The patient's family history of early-onset colorectal cancer in multiple first-degree relatives raises concern for possible hereditary syndrome, further supporting the shorter 3-year surveillance interval 1.

Surveillance Algorithm

1. First surveillance colonoscopy: 3 years after index colonoscopy

   • Due to adenoma ≥ 1 cm and strong family history

2. Subsequent surveillance intervals:

   • If follow-up colonoscopy is normal or shows only 1-2 small (<1 cm) tubular adenomas with low-grade dysplasia: extend interval to 5 years
   • If additional high-risk findings are present: maintain 3-year interval

Important Considerations

• Quality of baseline colonoscopy: Ensure the initial colonoscopy was complete to the cecum with adequate bowel preparation. If not, repeat examination should be performed before planning long-term surveillance 1

• Completeness of polypectomy: Confirm that the adenoma was completely removed. Incomplete removal is associated with increased risk of future cancers 1

• Discontinuation of surveillance: Consider the patient's overall health status and life expectancy when determining the appropriate time to discontinue surveillance 1

Common Pitfalls to Avoid

1. Underestimating the significance of adenoma size: Even with tubular histology and low-grade dysplasia, adenomas ≥1 cm warrant 3-year surveillance 1

2. Overlooking family history: The patient's strong family history of early-onset colorectal cancer should not be ignored when determining surveillance intervals 1

3. Overreliance on fecal occult blood testing: Guidelines discourage the use of FOBT during surveillance periods 1

4. Extending surveillance intervals too soon: Maintain the 3-year interval for the first surveillance colonoscopy before considering longer intervals based on subsequent findings 1