Manage small colorectal polyps based on patient age

In a cohort of more than 5,000 patients with a total of 755 colorectal polyps, 100% of malignancies were associated with polyps greater than or equal to 19 mm, in the issue of Clinical Gastroentorology and Hapatology.

Most of the polyps were smaller, however, with 61% of all lessons being 6-9 mm, the authors noted.

“These study included 5,124 consecutive asymptomatic adults undergoing computed tomography colonography (CTC) between April 2004 and July 2008. Patients’ mean age was 57 years, and 2,792 were women.

“Although individuals were not excluded for a positive family history of colorectal cancer, only 1.7% (89 adults) actually had a positive history according to [American Cancer Society] guidelines.”

Included in the analysis were all CTC-detected colorectal polyps greater than 6 mm that had corresponding endoscopic and/or surgical confirmation, “including lesions not prospectively identified at CTC but found at subsequent colonoscopy.”

“Mucosal-based polyps that were confirmed at colonoscopy but were lost during retrieval, fulgurated, or otherwise ablated were also excluded.”

A total of 755 lesions greater than or equal to 6mm were found in 479 patients. This included 464 lesions (61.5% that were 6-9mm, 216 lesions (4.4%) that measured 20-29 mm, and 42 (5.6%) that exceeded 30 mm.

According to the investigators, “In the small polyp group (6-9 mm), the rate of advanced adenomas was 3.9% (18 of 464).” Furthermore, only two polyps on this group were found to exhibit high-grade dysplasia, and none were classified as malignant.

That is in contrast to large polyps — those greater than 10 mm. Here “the overall rate of advanced adenomas and malignancy was significantly higher compared to the smaller polyp group, at 61.9% (180/291) and 6.9% (20/291), respectively (P less than .001 for both comparisons).”

This included two malignant polyps in the 10-19 mm group (for a prevalence of 0.9% in this group, out of 216 total polyps), and two malignancies in the 20-29 mm group (for a prevalence of 6.1% in this group, out of 33 total polyps — a significantly higher proportion than the 0.9% prevalence in the 10-19mm group, with P less than .001).

The remaining 16 malignancies were all found among the group of 42 polyps that measured greater than 30 mm, for a prevalence of 38.1%.

“For CTC-detected masses measuring 3 cm or greater, the risk of cancer clearly outweighs any procedural costs or risks related to its removal.”

However, “for CTC-detected colorectal lesions in the 1-2 cm and 2-3 cm size categories, the need for polypectomy referral has not been questioned in the past, although findings show that the immediate benefit may not be as great as previously assumed.”

“The guiding principal should be that carefully balance the risks and benefits to achieve an optimal outcome.”

The study was limited by the fact that the cohort included “average-risk screening subjects, higher rates of important histology would be expected amongst cohorts at increased risk for colorectal cancer.”

Additionally, “some polyps called at CTC are not found at subsequent colonoscopy,” though these account for “fewer than 10% of all CTC-detected lesions in experience.”