Long-term Risk of Colorectal Cancer After Removal of Conventional Adenomas and Serrated Polyps.

Gastroenterology
Authors
Keywords
Abstract

BACKGROUND & AIMS: Endoscopic screening reduces incidence and mortality of colorectal cancer (CRC) because precursor lesions, such as conventional adenomas or serrated polyps, are removed. Individuals with polypectomies are advised to undergo colonoscopy surveillance to prevent CRC. However, guidelines for surveillance intervals after diagnosis of a precursor lesion, particularly for individuals with serrated polyps, vary widely, and lack sufficient supporting evidence. Consequently, some high-risk patients do not receive enough surveillance and lower-risk subjects receive excessive surveillance.

METHODS: We examined the association between findings from first endoscopy and CRC risk among 122,899 participants who underwent flexible sigmoidoscopy or colonoscopy in the Nurses' Health Study 1 (1990-2012), Nurses' Health Study 2 (1989-2013), or the Health Professionals Follow-up Study (1990-2012). Endoscopic findings were categorized as no polyp, conventional adenoma, or serrated polyp (hyperplastic polyp, traditional serrated adenoma, or sessile serrated adenoma, with or without cytological dysplasia). Conventional adenomas were classified as advanced (≥10 mm, high-grade dysplasia, or tubulovillous or villous histology) or nonadvanced, and serrated polyps were assigned to categories of large (≥10 mm) or small (

RESULTS: After a median follow-up period of 10 years, we documented 491 incident cases of CRC: 51 occurred in 6161 participants with conventional adenomas, 24 in 5918 participants with serrated polyps, and 427 in 112,107 participants with no polyp. Compared with participants with no polyp detected during initial endoscopy, the multivariable HR for incident CRC in individuals with an advanced adenoma was 4.07 (95% confidence interval [CI] 2.89-5.72) and the HR for CRC in individuals with a large serrated polyp was 3.35 (95% CI 1.37-8.15). In contrast, there was no significant increase in risk of CRC in patients with nonadvanced adenomas (HR 1.21; 95% CI 0.68-2.16, P = .52) or small serrated polyps (HR 1.25; 95% CI 0.76-2.08; P = .38).

CONCLUSIONS: These findings provide support for guidelines that recommend repeat lower endoscopy within 3 years of a diagnosis of advanced adenoma and large serrated polyps. In contrast, patients with nonadvanced adenoma or small serrated polyps may not require more intensive surveillance than patients without polyps.

Year of Publication
2020
Journal
Gastroenterology
Volume
158
Issue
4
Pages
852-861.e4
Date Published
2020 03
ISSN
1528-0012
DOI
10.1053/j.gastro.2019.06.039
PubMed ID
31302144
PubMed Central ID
PMC6954345
Links
Grant list
R35 CA197735 / CA / NCI NIH HHS / United States
R01 CA202704 / CA / NCI NIH HHS / United States
L30 CA209764 / CA / NCI NIH HHS / United States
K24 DK098311 / DK / NIDDK NIH HHS / United States
UM1 CA186107 / CA / NCI NIH HHS / United States
R03 CA197879 / CA / NCI NIH HHS / United States
P50 CA127003 / CA / NCI NIH HHS / United States
R21 CA230873 / CA / NCI NIH HHS / United States
P01 CA087969 / CA / NCI NIH HHS / United States
P01 CA055075 / CA / NCI NIH HHS / United States
R01 CA151993 / CA / NCI NIH HHS / United States
U01 CA176726 / CA / NCI NIH HHS / United States
R01 CA137178 / CA / NCI NIH HHS / United States
R01 CA176272 / CA / NCI NIH HHS / United States
T32 CA009001 / CA / NCI NIH HHS / United States
UM1 CA167552 / CA / NCI NIH HHS / United States
K99 CA215314 / CA / NCI NIH HHS / United States
R00 CA215314 / CA / NCI NIH HHS / United States