colorectal adenomatous polyp; tubular adenoma; villous adenoma
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Etiology
- risk factors
- antibiotic use in young adulthood & middle age
- dose-dependent relationship
- antibiotic use in young adulthood & middle age
Histology
* villous adenomatous polyps are more frequently sessile polyps & develop into adenocarcinoma 3 times more frequently than tubular adenomatous polyps
* images (review)[9]
Pathology
Most colorectal carcinomas begin as adenomatous polyps. Only a minority of adenomatous polyps develop into cancer (< 1%).
Gross morphology:
- pedunculated
- sessile (flat)*
* Cancers develop more frequently from sessile polyps.
Genetics
- siblings of patients with advanced adenomatous polyps are at increased risk for advanced colorectal adenomas[8]
Clinical manifestations
- most colonic adenomatous polyps produce no symptoms
Prognosis:
- < 1.5 cm: low probability of transformation
- 1.5-2.5 cm: 2-10% probability of transformation*
- > 2.5 cm: > 10% probability of transformation*
* colorectal cancer risk increased only for adenomas >= 20 mm or with high-grade dysplasia[13]
relative risk for advanced adenoma 36 months later[11]
- 1-2 adenomas, of which at least 1 was small (5-9 mm) = 1.5
- 3-10 small adenomas (5-9 mm) = 1.7
- 3-10 adenomas, of which at least 1 was small (5-9 mm) = 2.0
- advanced adenoma = 2.5
colorectal cancer risk & (mortality) for index colonoscopy[14]
- no adenoma = 3.4 (0.7)
- 1-2 small adenomas < 10 mm = 4.5 (0.8)
- > 3 adenomas or adenoma > 10 mm or villous features or high-grade dysplasia = 13.8 (2.1)
Management
- entire bowel should be visualized by colonoscopy since multiple lesions are present in 1/3 of cases
- repeat colonoscopy
- 1-2 small tubular adenomas, follow-up colonoscopy in 5-10 years[6]
- 5 years is reasonable[12]
- 3-10 adenomas, any adenoma with villous elements or high-grade dysplasia, or an adenoma measuring >= 1 cm should have another exam in 3 years[3]
- > 10 adenomas, & those with large sessile adenomas removed piecemeal, should have a follow-up in < 3 years
- sessile adenomas removed in piecemeal fashion should have follow-up in 2-6 months
- large adenomas (> 2 cm) or well differentiated colorectal adenocarcinomas with clean margins should have follow-up exam in 3-6 months[5]
- information from previous exams may be useful[4]
- 1-2 small tubular adenomas, follow-up colonoscopy in 5-10 years[6]
- prevention
More general terms
More specific terms
Additional terms
References
- ↑ Harrison's Principles of Internal Medicine, 13th ed. Isselbacher et al (eds), McGraw-Hill Inc. NY, 1994, pg 1426
- ↑ Internal Medicine News, Dec 1, 2005 quotes Bakhru M, at the annual meeting of the American College of Gastroenterology
- ↑ 3.0 3.1 Laiyemo AO, Murphy G, Albert PS, Sansbury LB, Wang Z et al Postpolypectomy colonoscopy surveillance guidelines: predictive accuracy for advanced adenoma at 4 years. Ann Intern Med. 2008 Mar 18;148(6):419-26. PMID: https://www.ncbi.nlm.nih.gov/pubmed/18347350
Imperiale TF, Sox HC. Guidelines for surveillance intervals after polypectomy: coping with the evidence. Ann Intern Med. 2008 Mar 18;148(6):477-9. No abstract available. PMID: https://www.ncbi.nlm.nih.gov/pubmed/18347353 - ↑ 4.0 4.1 Robertson DJ et al. Using the results of a baseline and a surveillance colonoscopy to predict recurrent adenomas with high-risk characteristics. Ann Intern Med 2009 Jul 21; 151:103. PMID: https://www.ncbi.nlm.nih.gov/pubmed/19620162
- ↑ 5.0 5.1 Medical Knowledge Self Assessment Program (MKSAP) 15, 16, 17. American College of Physicians, Philadelphia 2009, 2012, 2015
- ↑ 6.0 6.1 Chung SJ et al. Five-year risk for advanced colorectal neoplasia after initial colonoscopy according to the baseline risk stratification: A prospective study in 2452 asymptomatic Koreans. Gut 2011 Nov; 60:1537. PMID: https://www.ncbi.nlm.nih.gov/pubmed/21427200
Winawer SJ et al Guidelines for Colonoscopy Surveillance After Polypectomy: A Consensus Update by the US Multi-Society Task Force on Colorectal Cancer and the American Cancer Society Gastroenterology, 2006, 130(6):1872-1885 <PubMed> PMID: https://www.ncbi.nlm.nih.gov/pubmed/16697750 <Internet> http://www.gastrojournal.org/article/S0016-5085(06)00561-0/abstract - ↑ 7.0 7.1 Baron JA, Barry EL, Mott LA et al A Trial of Calcium and Vitamin D for the Prevention of Colorectal Adenomas. N Engl J Med 2015; 373:1519-1530. October 15, 2015 <PubMed> PMID: https://www.ncbi.nlm.nih.gov/pubmed/26465985 <Internet> http://www.nejm.org/doi/full/10.1056/NEJMoa1500409
- ↑ 8.0 8.1 Ng SC et al. Risk of advanced adenomas in siblings of individuals with advanced adenomas: A cross-sectional study. Gastroenterology 2015 Nov 13 PMID: https://www.ncbi.nlm.nih.gov/pubmed/26584600
- ↑ 9.0 9.1 Strum WB Colorectal Adenomas (images) N Engl J Med 2016; 374:1065-1075. March 17, 2016 <PubMed> PMID: https://www.ncbi.nlm.nih.gov/pubmed/26981936 <Internet> http://www.nejm.org/doi/full/10.1056/NEJMra1513581
- ↑ Cao Y, Wu K, Mehta R et al Long-term use of antibiotics and risk of colorectal adenoma Gut. April 2017 <PubMed> PMID: https://www.ncbi.nlm.nih.gov/pubmed/28377387 <Internet> http://gut.bmj.com/content/early/2017/03/16/gutjnl-2016-313413
- ↑ 11.0 11.1 Anderson JC, Rex DK, Robinson C, Butterly LF. Association of small versus diminutive adenomas and the risk for metachronous advanced adenomas: Data from the New Hampshire Colonoscopy Registry. Gastrointest Endosc 2019 May 21; PMID: https://www.ncbi.nlm.nih.gov/pubmed/31125546 https://www.giejournal.org/article/S0016-5107(19)31721-3/pdf
Sekiguchi M, Otake Y, Kakugawa Y, Matsumoto M et al. Incidence of advanced colorectal neoplasia in individuals with untreated diminutive colorectal adenomas diagnosed by magnifying image-enhanced endoscopy. Am J Gastroenterol 2019 Jun; 114:964 PMID: https://www.ncbi.nlm.nih.gov/pubmed/31082873 - ↑ 12.0 12.1 Meester RGS, Lansdorp-Vogelaar I, Winawer SJ et al High-Intensity Versus Low-Intensity Surveillance for Patients With Colorectal Adenomas: A Cost-Effectiveness Analysis. Ann Intern Med. 2019. Sept 24 PMID: https://www.ncbi.nlm.nih.gov/pubmed/31546257 https://annals.org/aim/article-abstract/2751914/high-intensity-versus-low-intensity-surveillance-patients-colorectal-adenomas-cost
Weinberg DS, Schoen RE Preneoplastic Colorectal Polyps: "I Found Them and Removed Them - Now What?" Ann Intern Med. 2019. Sept 24 PMID: https://www.ncbi.nlm.nih.gov/pubmed/31546250 https://annals.org/aim/article-abstract/2751915/preneoplastic-colorectal-polyps-i-found-them-removed-them-now-what - ↑ 13.0 13.1 Wieszczy P, P, Kaminski MF, Franczyk R et al. Colorectal cancer incidence and mortality after removal of adenomas during screening colonoscopies. Gastroenterology. 2019 Sep 26. pii: S0016-5085(19)41344-9. PMID: https://www.ncbi.nlm.nih.gov/pubmed/31563625 Free Article
- ↑ 14.0 14.1 Duvvuri A, Chandrasekar VT, Srinivasan S et al. Risk of colorectal cancer and cancer related mortality after detection of low-risk or high-risk adenomas, compared with no adenoma, at index colonoscopy: A systematic review and meta-analysis. Gastroenterology 2021 Jan 29; [e-pub] PMID: https://www.ncbi.nlm.nih.gov/pubmed/33524401 https://www.gastrojournal.org/article/S0016-5085(21)00320-6/pdf
- ↑ Lieberman DA, Rex DK, Winawer SJ et al. Guidelines for Colonoscopy Surveillance After Screening and Polypectomy: A Consensus Update by the US Multi-Society Task Force on Colorectal Cancer. Gastroenterology. 2012 143(3):844-857 PMID: https://www.ncbi.nlm.nih.gov/pubmed/22763141 https://www.gastrojournal.org/article/S0016-5085(12)00812-8/fulltext