Table of ContentsView AllTable of ContentsSizing ChartCancer RiskMultiple PolypsColonoscopy TimelineNext Steps
Table of ContentsView All
View All
Table of Contents
Sizing Chart
Cancer Risk
Multiple Polyps
Colonoscopy Timeline
Next Steps
Polyps in the colon and rectum (together calledcolorectal polyps) are common in people over age 50. They are usually noncancerous, but certain characteristics can increase the likelihood of a polyp becoming cancerous.
The risk of a polyp becoming cancerous increases with size. Polyps that are 10 millimeters (mm) or larger are considered to have a higher cancer risk than ones that are smaller than 10 mm.
Sizing Chart for Different Colon Polyps
Colorectal polypsare categorized into three sizes:
Polyps that are found to be more than 30 mm (3 centimeters (cm)) on endoscopy (a procedure that uses a flexible tube to explore the digestive tract) can be labeled giant polyps.
Polyps can be divided into four shape categories:
What Are Complex Polyps?
Complex polyps (also called defiant polyps) have one or more of the following features:
What Colon Polyp Size Could Be Cancerous?
Having a colorectal polyp doesn’t necessarily mean cancer will develop. Most polyps do not become cancerous, and it can take years for the polyps that do to become cancerous.
In addition to the type of polyp, the characteristics typically focused on to determine the potentialcancer risk of a polypinclude:
Cancer develops when mutations occur in quickly dividing cells. Cells that contain an error in their DNA continue to divide and replicate, where the chance for more errors can occur. These errors, accumulating over time, can lead to cancer. A large polyp has been around longer and is made of larger masses of cells, so the opportunity for cancer to develop through these cellular changes is higher. Multiple polyps also create more opportunities for errors to occur.
In general terms, colorectal polyps that are 10 mm (1 cm) or bigger in diameter are considered to have a higher risk ofbecoming cancerousthan those smaller than 10 mm.Adenomasand sessile serrated polyps that are 10 mm or more are classified as advanced.
The risk that a polyp will become cancerous can continue to rise with the size of the polyp. Depending on the type and other factors, up to 50% of polyps over 20 mm (2 cm) are cancerous.
Some research has found that the incidence of polyp cancer is up to 75% when a polyp reaches 35 mm (3.5 cm).
Other considerations can influence these risks. For instance, Tubular adenomas areassociated with cancerin about 5% of cases, while the rate for villous adenomas can be up to 40%.
Some research has found the risk of a polyp becoming cancerous is particularly high when adenomas:
Research findings have also suggested that advanced adenomas progress to cancer at ahigher ratethan the average rate for all adenomas, and this advanced rate increases with the age of the person. Advanced adenomas are defined as having at least one of these criteria:
Though polyps 10 cm or larger in size carry a higher risk of cancer, most adenomas (60% to 75%) detected with colonoscopy are smaller than 10 cm.
Smaller polyps are still routinely removed during colonoscopies.
Implications of Multiple Colon Polyps
The number of colorectal polyps has several implications.
The number of polyps can affect the recommendations for future screening, particularly in conjunction with other factors such as size. For example, if there are three to four small polyps, a follow-up colonoscopy may be suggested for three years, whereas the presence of five or more small polyps may prompt a recommended repeat colonoscopy in a year.
The risk of cancer development can increase with multiple polyps, as well as the risk of developing more polyps in the future, with more than 10 adenomas considered the highest risk.
Certain conditions, calledpolyposissyndromes, are associated with multiple polyps. These include:
Other Risk Factors for Colorectal CancerRisk factors for colorectal polyps and/orcolorectal cancerinclude:Age (most cases are in people 45 years and older, and incidence increases with age)Ethnicity (higher rates of colorectal cancer in Black adults and American Indian and Alaskan Native adults)DiabetesPersonal and/or family history of polyps orcolorectal cancerRare, inherited genes or conditions that increase the likelihood of developing polypsAn inflammatory bowel diseaseA high-fat, low-fiber dietTobacco and/or alcohol useObesityLittle or no regular exercise
Other Risk Factors for Colorectal Cancer
Risk factors for colorectal polyps and/orcolorectal cancerinclude:Age (most cases are in people 45 years and older, and incidence increases with age)Ethnicity (higher rates of colorectal cancer in Black adults and American Indian and Alaskan Native adults)DiabetesPersonal and/or family history of polyps orcolorectal cancerRare, inherited genes or conditions that increase the likelihood of developing polypsAn inflammatory bowel diseaseA high-fat, low-fiber dietTobacco and/or alcohol useObesityLittle or no regular exercise
Risk factors for colorectal polyps and/orcolorectal cancerinclude:
How Soon Do You Learn Colon Polyp Size After Colonoscopy?
If a polyp is found during a colonoscopy, the medical professional (typically an endoscopist) will measure the polyp during the procedure.
Next Steps: Determining the Size of a Colon Polyp
If a polyp or other abnormality was found on ascreening test, more tests may be necessary, including a colonoscopy if one has not already been performed.
It isn’t possible to know if a polyp will become cancerous, so polyps are usually removed. This is typically done during the colonoscopy, using simple devices such as forceps or snares, introduced through the scope.
If the polyp or polyps are of abnormal size or in areas that are difficult to access, they may require more specialized procedures to remove or treat them, including:
Rarely, surgery toremove the part of the colonthat contains the polyp(s) (called a partial colectomy) may be necessary if the polyp(s) are very likely to become cancerous or are too large to remove during the colonoscopy.
If polyps are found and removed duringa colonoscopy, there is a 25% to 30% chance that polyps will be found in future colonoscopies as well. This means your healthcare provider may suggest you have another colonoscopy sooner than the 10-year interval suggested if no polyps are found.
Factors that help determine the best course of action after polyps are found and when thenext colonoscopy should be performedinclude:
It is very important to follow the directions of your healthcare provider in terms of follow-up to your colonoscopy and any further testing ortreatments. Early detection and removal of colorectal polyps can reduce your chances of developing colorectal cancer.
Summary
The size of a colorectal polyp is one of several important factors in determining the risk of the polyp becomingcancerous. Generally speaking, polyps 10 mm or bigger are more likely to become cancerous than those smaller than 10 mm, but this can vary depending on other characteristics, such as the type of polyp.
Some harder-to-remove polyps may require more specialized procedures.
If one or more polyps are found, another colonoscopy is usually recommended before the standard 10-year intervals suggested when no polyps were found. Listen to your healthcare provider and follow their directions for follow-ups and further testing.
Routine testing for polyps and colorectal cancer, as well as proper follow-ups, are very important because early detection and removal of polyps can decrease the risk of the development ofcolorectal cancer.
23 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Mount Sinai.Colorectal polyps.von Renteln D, Pohl H.Polyp resection - controversial practices and unanswered questions. Clinical and Translational Gastroenterology. 2017;8(3):e76. doi:10.1038%2Fctg.2017.6Lee J.Resection of diminutive and small colorectal polyps: What is the optimal technique?Clin Endosc. 2016;49(4):355-358. doi:10.5946/ce.2016.063Bains L, Lal P, Vindal A, Singh M.Giant villous adenoma of rectum- what is the malignant potential and what is the optimal treatment? A case and review of literature. World J Surg Onc. 2019;17(1):109. doi.org/10.1186/s12957-019-1650-4University of Texas MD Anderson Cancer Center.Colon polyps: 10 things to know.University of Michigan Health.Colon and rectal polyps.UpToDate.Patient education: colon polyps (Beyond the Basics).University of Michigan, Michigan Medicine.A colon polyp primer: know the types and your risk factors.Bonnington SN, Rutter MD.Surveillance of colonic polyps: Are we getting it right?WJG. 2016;22(6):1925. 10.3748/wjg.v22.i6.1925American Cancer Society.Colorectal cancer.Johnson GGRJ, Helewa R, Moffatt DC, et al.Colorectal polyp classification and management of complex polyps for surgeon endoscopists. cjs. 2023;66(5):E491-E498. doi:10.1503/cjs.011422Yale Medicine.3 things to know about colon polyps.Shaw MJ, Shaukat A.Does polyp size scatter matter?Gastrointestinal Endoscopy. 2016;83(1):209-211. doi:10.1016/j.gie.2015.08.060National Cancer Institute.Abstracting keys.Salmo E, Haboubi N.Adenoma and malignant colorectal polyp: pathological considerations and clinical applications. EMJ Gastroenterol. Published online December 11, 2018:92-102. doi:10.33590/emjgastroenterol/10313443Shussman N, Wexner SD.Colorectal polyps and polyposis syndromes. Gastroenterology Report. 2014;2(1):1-15. doi:10.1093/gastro/got041Otero-Regino W, Oino-Embus L, Parra-Otero L.A simple new method to accurately measure the size of polyps during colonoscopy. Rev Colomb Gastroenterol. 2018;33(3):199. doi:10.22516/25007440.286American Society of Colon and Rectal Surgeons.Screening and surveillance for colorectal cancer expanded information.Davidson KW.Screening for colorectal cancer: US Preventive Services Task Force Recommendation Statement. JAMA. 2021;325(19):1965. doi:10.1001/jama.2021.6238National Health Service.Bowel polyps.National Cancer Institute.Screening tests to detect colorectal cancer and polyps.Stanford Medicine.Colon polyps treatment.Harvard Health Publishing.They found colon polyps: Now what?
23 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Mount Sinai.Colorectal polyps.von Renteln D, Pohl H.Polyp resection - controversial practices and unanswered questions. Clinical and Translational Gastroenterology. 2017;8(3):e76. doi:10.1038%2Fctg.2017.6Lee J.Resection of diminutive and small colorectal polyps: What is the optimal technique?Clin Endosc. 2016;49(4):355-358. doi:10.5946/ce.2016.063Bains L, Lal P, Vindal A, Singh M.Giant villous adenoma of rectum- what is the malignant potential and what is the optimal treatment? A case and review of literature. World J Surg Onc. 2019;17(1):109. doi.org/10.1186/s12957-019-1650-4University of Texas MD Anderson Cancer Center.Colon polyps: 10 things to know.University of Michigan Health.Colon and rectal polyps.UpToDate.Patient education: colon polyps (Beyond the Basics).University of Michigan, Michigan Medicine.A colon polyp primer: know the types and your risk factors.Bonnington SN, Rutter MD.Surveillance of colonic polyps: Are we getting it right?WJG. 2016;22(6):1925. 10.3748/wjg.v22.i6.1925American Cancer Society.Colorectal cancer.Johnson GGRJ, Helewa R, Moffatt DC, et al.Colorectal polyp classification and management of complex polyps for surgeon endoscopists. cjs. 2023;66(5):E491-E498. doi:10.1503/cjs.011422Yale Medicine.3 things to know about colon polyps.Shaw MJ, Shaukat A.Does polyp size scatter matter?Gastrointestinal Endoscopy. 2016;83(1):209-211. doi:10.1016/j.gie.2015.08.060National Cancer Institute.Abstracting keys.Salmo E, Haboubi N.Adenoma and malignant colorectal polyp: pathological considerations and clinical applications. EMJ Gastroenterol. Published online December 11, 2018:92-102. doi:10.33590/emjgastroenterol/10313443Shussman N, Wexner SD.Colorectal polyps and polyposis syndromes. Gastroenterology Report. 2014;2(1):1-15. doi:10.1093/gastro/got041Otero-Regino W, Oino-Embus L, Parra-Otero L.A simple new method to accurately measure the size of polyps during colonoscopy. Rev Colomb Gastroenterol. 2018;33(3):199. doi:10.22516/25007440.286American Society of Colon and Rectal Surgeons.Screening and surveillance for colorectal cancer expanded information.Davidson KW.Screening for colorectal cancer: US Preventive Services Task Force Recommendation Statement. JAMA. 2021;325(19):1965. doi:10.1001/jama.2021.6238National Health Service.Bowel polyps.National Cancer Institute.Screening tests to detect colorectal cancer and polyps.Stanford Medicine.Colon polyps treatment.Harvard Health Publishing.They found colon polyps: Now what?
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Mount Sinai.Colorectal polyps.von Renteln D, Pohl H.Polyp resection - controversial practices and unanswered questions. Clinical and Translational Gastroenterology. 2017;8(3):e76. doi:10.1038%2Fctg.2017.6Lee J.Resection of diminutive and small colorectal polyps: What is the optimal technique?Clin Endosc. 2016;49(4):355-358. doi:10.5946/ce.2016.063Bains L, Lal P, Vindal A, Singh M.Giant villous adenoma of rectum- what is the malignant potential and what is the optimal treatment? A case and review of literature. World J Surg Onc. 2019;17(1):109. doi.org/10.1186/s12957-019-1650-4University of Texas MD Anderson Cancer Center.Colon polyps: 10 things to know.University of Michigan Health.Colon and rectal polyps.UpToDate.Patient education: colon polyps (Beyond the Basics).University of Michigan, Michigan Medicine.A colon polyp primer: know the types and your risk factors.Bonnington SN, Rutter MD.Surveillance of colonic polyps: Are we getting it right?WJG. 2016;22(6):1925. 10.3748/wjg.v22.i6.1925American Cancer Society.Colorectal cancer.Johnson GGRJ, Helewa R, Moffatt DC, et al.Colorectal polyp classification and management of complex polyps for surgeon endoscopists. cjs. 2023;66(5):E491-E498. doi:10.1503/cjs.011422Yale Medicine.3 things to know about colon polyps.Shaw MJ, Shaukat A.Does polyp size scatter matter?Gastrointestinal Endoscopy. 2016;83(1):209-211. doi:10.1016/j.gie.2015.08.060National Cancer Institute.Abstracting keys.Salmo E, Haboubi N.Adenoma and malignant colorectal polyp: pathological considerations and clinical applications. EMJ Gastroenterol. Published online December 11, 2018:92-102. doi:10.33590/emjgastroenterol/10313443Shussman N, Wexner SD.Colorectal polyps and polyposis syndromes. Gastroenterology Report. 2014;2(1):1-15. doi:10.1093/gastro/got041Otero-Regino W, Oino-Embus L, Parra-Otero L.A simple new method to accurately measure the size of polyps during colonoscopy. Rev Colomb Gastroenterol. 2018;33(3):199. doi:10.22516/25007440.286American Society of Colon and Rectal Surgeons.Screening and surveillance for colorectal cancer expanded information.Davidson KW.Screening for colorectal cancer: US Preventive Services Task Force Recommendation Statement. JAMA. 2021;325(19):1965. doi:10.1001/jama.2021.6238National Health Service.Bowel polyps.National Cancer Institute.Screening tests to detect colorectal cancer and polyps.Stanford Medicine.Colon polyps treatment.Harvard Health Publishing.They found colon polyps: Now what?
Mount Sinai.Colorectal polyps.
von Renteln D, Pohl H.Polyp resection - controversial practices and unanswered questions. Clinical and Translational Gastroenterology. 2017;8(3):e76. doi:10.1038%2Fctg.2017.6
Lee J.Resection of diminutive and small colorectal polyps: What is the optimal technique?Clin Endosc. 2016;49(4):355-358. doi:10.5946/ce.2016.063
Bains L, Lal P, Vindal A, Singh M.Giant villous adenoma of rectum- what is the malignant potential and what is the optimal treatment? A case and review of literature. World J Surg Onc. 2019;17(1):109. doi.org/10.1186/s12957-019-1650-4
University of Texas MD Anderson Cancer Center.Colon polyps: 10 things to know.
University of Michigan Health.Colon and rectal polyps.
UpToDate.Patient education: colon polyps (Beyond the Basics).
University of Michigan, Michigan Medicine.A colon polyp primer: know the types and your risk factors.
Bonnington SN, Rutter MD.Surveillance of colonic polyps: Are we getting it right?WJG. 2016;22(6):1925. 10.3748/wjg.v22.i6.1925
American Cancer Society.Colorectal cancer.
Johnson GGRJ, Helewa R, Moffatt DC, et al.Colorectal polyp classification and management of complex polyps for surgeon endoscopists. cjs. 2023;66(5):E491-E498. doi:10.1503/cjs.011422
Yale Medicine.3 things to know about colon polyps.
Shaw MJ, Shaukat A.Does polyp size scatter matter?Gastrointestinal Endoscopy. 2016;83(1):209-211. doi:10.1016/j.gie.2015.08.060
National Cancer Institute.Abstracting keys.
Salmo E, Haboubi N.Adenoma and malignant colorectal polyp: pathological considerations and clinical applications. EMJ Gastroenterol. Published online December 11, 2018:92-102. doi:10.33590/emjgastroenterol/10313443
Shussman N, Wexner SD.Colorectal polyps and polyposis syndromes. Gastroenterology Report. 2014;2(1):1-15. doi:10.1093/gastro/got041
Otero-Regino W, Oino-Embus L, Parra-Otero L.A simple new method to accurately measure the size of polyps during colonoscopy. Rev Colomb Gastroenterol. 2018;33(3):199. doi:10.22516/25007440.286
American Society of Colon and Rectal Surgeons.Screening and surveillance for colorectal cancer expanded information.
Davidson KW.Screening for colorectal cancer: US Preventive Services Task Force Recommendation Statement. JAMA. 2021;325(19):1965. doi:10.1001/jama.2021.6238
National Health Service.Bowel polyps.
National Cancer Institute.Screening tests to detect colorectal cancer and polyps.
Stanford Medicine.Colon polyps treatment.
Harvard Health Publishing.They found colon polyps: Now what?
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