Risk of cancer in small and diminutive colorectal polyps

Abstract

The prevalence of cancer in small and diminutive polyps is relevant to "resect and discard" and CT colonography reporting recommendations.We evaluated a prospectively collected colonoscopy polyp database to identify polyps < 10 mm and those with cancer or advanced histology (high-grade dysplasia or villous elements)Of 32,790 colonoscopies, 15,558 colonoscopies detected 42,630 polyps < 10 mm in size. A total of 4,790 lesions were excluded as they were not conventional adenomas or serrated class lesions.There were 23,524 conventional adenomas < 10 mm of which 22,952 were tubular adenomas.There were 14,316 serrated class lesions of which 13,589 were hyperplastic polyps and the remainder were sessile serrated polyps. Of all conventional adenomas, 96 had high-grade dysplasia including 0.3% of adenomas ≤ 5 mm in size and 0.8% of adenomas 6-9 mm in size. Of all conventional adenomas, 2.1% of those ≤ 5 mm in size and 5.6% of those 6-9 mm in size were advanced. Among 36,107 polyps ≤ 5 mm in size and 6,523 polyps 6-9 mm in size, there were no cancers.These results support the safety of resect and discard as well as current CT colonography reporting recommendations for small and diminutive polyps.

Colorectal Cancer Screening: Recommendations for Physicians and Patients from the U.S. Multi-Society Task Force on Colorectal Cancer

“…Villous elements and invasive cancer are associated with increasing size of adenomas. Invasive cancer in adenomas ≤5 mm in size is extremely rare, and the prevalence remains well below 1% in adenomas 6 to 9 mm in size ( 36 ). Recent colonoscopic studies have identifi ed lower prevalence rates of cancer in polyps <1 cm in size compared with early studies, probably because improvements in colonoscope technology and performance have led to routine detection of an array of small, fl at, low-volume adenomas ( 36 ).…”

“…Invasive cancer in adenomas ≤5 mm in size is extremely rare, and the prevalence remains well below 1% in adenomas 6 to 9 mm in size ( 36 ). Recent colonoscopic studies have identifi ed lower prevalence rates of cancer in polyps <1 cm in size compared with early studies, probably because improvements in colonoscope technology and performance have led to routine detection of an array of small, fl at, low-volume adenomas ( 36 ). Interobserver agreement in diff erentiation of high-vs. low-grade dysplasia by pathologists and tubular vs. tubulovillous histology is poor to moderate, particularly in adenomas <1 cm in size ( 37 ).…”

What Is the Hang-Up With Optical Diagnosis of Diminutive Colorectal Polyps?

“…Diminutive colorectal polyps are the most commonly found polyps during colonoscopy 6 and rarely harbor advanced histology or malignancy. 7 If diminutive polyp histology can be determined in real time, polyps confidently diagnosed as adenomas can be resected and discarded, and non-neoplastic polyps in the rectosigmoid colon can be left in place, leading to enormous cost savings. 8,9 Endoscopists can always send polyps for pathology if the optical diagnosis is not clear.…”

Polyp Resection - Controversial Practices and Unanswered Questions

“…10, 11, 12, 13, 14, 15, 16, 17 A recent and largest cross-sectional study to date included >42,000 polypectomies of up to 9 mm polyps did not find any cancer in any of these diminutive or small polyps. 18 Resection of diminutive polyps increases patient risk and cost, yet the benefit on cancer prevention by removing diminutive polyps is questionable. 15, 19, 20 However, histopathology evaluation of diminutive polyps remains important because presence of adenoma may determine low- or high-risk status of the patient and affect the colonoscopy surveillance interval.…”