Title: Screening and Surveillance for the Early Detection of Colorectal Cancer and Adenomatous Polyps, 2008: A Joint Guideline From the American Cancer Society, the US Multi-Society Task Force on Colorectal Cancer, and the American College of Radiology
Abstract: In the United States, colorectal cancer (CRC) is the third most common cancer diagnosed among men and women and the second leading cause of death from cancer. CRC largely can be prevented by the detection and removal of adenomatous polyps, and survival is significantly better when CRC is diagnosed while still localized. In 2006 to 2007, the American Cancer Society, the US Multi-Society Task Force on Colorectal Cancer, and the American College of Radiology came together to develop consensus guidelines for the detection of adenomatous polyps and CRC in asymptomatic average-risk adults. In this update of each organization's guidelines, screening tests are grouped into those that primarily detect cancer early and those that can detect cancer early and also can detect adenomatous polyps, thus providing a greater potential for prevention through polypectomy. When possible, clinicians should make patients aware of the full range of screening options, but at a minimum they should be prepared to offer patients a choice between a screening test that primarily is effective at early cancer detection and a screening test that is effective at both early cancer detection and cancer prevention through the detection and removal of polyps. It is the strong opinion of these 3 organizations that colon cancer prevention should be the primary goal of screening. In the United States, colorectal cancer (CRC) is the third most common cancer diagnosed among men and women and the second leading cause of death from cancer. CRC largely can be prevented by the detection and removal of adenomatous polyps, and survival is significantly better when CRC is diagnosed while still localized. In 2006 to 2007, the American Cancer Society, the US Multi-Society Task Force on Colorectal Cancer, and the American College of Radiology came together to develop consensus guidelines for the detection of adenomatous polyps and CRC in asymptomatic average-risk adults. In this update of each organization's guidelines, screening tests are grouped into those that primarily detect cancer early and those that can detect cancer early and also can detect adenomatous polyps, thus providing a greater potential for prevention through polypectomy. When possible, clinicians should make patients aware of the full range of screening options, but at a minimum they should be prepared to offer patients a choice between a screening test that primarily is effective at early cancer detection and a screening test that is effective at both early cancer detection and cancer prevention through the detection and removal of polyps. It is the strong opinion of these 3 organizations that colon cancer prevention should be the primary goal of screening. In the United States, colorectal cancer (CRC) is the third most common cancer diagnosed in men and women and the second leading cause of death from cancer.1Jemal A. Siegel R. Ward E. et al.Cancer statistics, 2008.CA Cancer J Clin. 2008; 58: 71-96Google Scholar In 2008, it is estimated that 148,810 men and women will be diagnosed with CRC and 49,960 will die from this disease.1Jemal A. Siegel R. Ward E. et al.Cancer statistics, 2008.CA Cancer J Clin. 2008; 58: 71-96Google Scholar Five-year survival is 90% if the disease is diagnosed while still localized (ie, confined to the wall of the bowel) but only 68% for regional disease (ie, disease with lymph node involvement) and only 10% if distant metastases are present.2Ries L. Melbert D. Krapcho M. et al.SEER Cancer Statistics Review, 1975–2004.in: National Cancer Institute, Bethesda, MD2007Google Scholar Recent trends in CRC incidence and mortality reveal declining rates, which have been attributed to reduced exposure to risk factors, the effect of screening on early detection and prevention through polypectomy, and improved treatment.3Espey D.K. Wu X.C. Swan J. et al.Annual report to the nation on the status of cancer, 1975–2004, featuring cancer in American Indians and Alaska Natives.Cancer. 2007; 110: 2119-2152Google Scholar However, in the near term, even greater incidence and mortality reductions could be achieved if a greater proportion of adults received regular screening. Although prospective randomized trials and observational studies have demonstrated mortality reductions associated with early detection of invasive disease, as well as removal of adenomatous polyps,4Selby J.V. Friedman G.D. Quesenberry Jr, C.P. Weiss N.S. A case-control study of screening sigmoidoscopy and mortality from colorectal cancer.N Engl J Med. 1992; 326: 653-657Google Scholar, 5Hardcastle J.D. Chamberlain J.O. Robinson M.H. et al.Randomised controlled trial of faecal-occultblood screening for colorectal cancer.Lancet. 1996; 348: 1472-1477Google Scholar, 6Kronborg O. Fenger C. Olsen J. et al.Randomised study of screening for colorectal cancer with faecaloccult- blood test.Lancet. 1996; 348: 1467-1471Google Scholar, 7Mandel J.S. Church T.R. Bond J.H. et al.The effect of fecal occult-blood screening on the incidence of colorectal cancer.N Engl J Med. 2000; 343: 1603-1607Google Scholar a majority of US adults are not receiving regular age- and risk-appropriate screening or have never been screened at all.8Meissner H.I. Breen N. Klabunde C.N. Vernon S.W. Patterns of colorectal cancer screening uptake among men and women in the United States.Cancer Epidemiol Biomarkers Prev. 2006; 15: 389-394Google Scholar, 9Smith R.A. Cokkinides V. Eyre H.J. Cancer screening in the United States, 2007: a review of current guidelines, practices, and prospects.CA Cancer J Clin. 2007; 57: 90-104Google Scholar The goal of cancer screening is to reduce mortality through a reduction in incidence of advanced disease. To this end, modern CRC screening can achieve this goal through the detection of early-stage adenocarcinomas and the detection and removal of adenomatous polyps, the latter generally accepted as a nonobligate precursor lesion. Adenomatous polyps are common in adults over age 50 years, but the majority of polyps will not develop into adenocarcinoma; histology and size determine their clinical importance.10O'Brien M.J. Winawer S.J. Zauber A.G. et al.The National Polyp StudyPatient and polyp characteristics associated with high-grade dysplasia in colorectal adenomas.Gastroenterology. 1990; 98: 371-379Crossref Scopus (716) Google Scholar, 11Bond J.H. Colon polyps and cancer.Endoscopy. 2003; 35: 27-35Google Scholar The most common and clinically important polyps are adenomatous polyps, which represent approximately one half to two thirds of all colorectal polyps and are associated with a higher risk of CRC. Thus, most CRC screening studies evaluate the detection rate of invasive CRCs as well as advanced adenomas, which conventionally are defined as polyps ≥10 mm or histologically having high-grade dysplasia or significant villous components. The evidence for the importance of colorectal polyps in the development of CRC is largely indirect, but nonetheless extensive and convincing, and has been described in detail.11Bond J.H. Colon polyps and cancer.Endoscopy. 2003; 35: 27-35Google Scholar, 12Winawer S.J. Fletcher R.H. Miller L. et al.Colorectal cancer screening: clinical guidelines and rationale.Gastroenterology. 1997; 112: 594-642Abstract Full Text Full Text PDF Scopus (1815) Google Scholar, 13Winawer S.J. Natural history of colorectal cancer.Am J Med. 1999; 106: 3S-6SGoogle Scholar Today there is a range of options for CRC screening in the average-risk population, with current technology falling into 2 general categories: stool tests, which include tests for occult blood or exfoliated DNA, and structural exams, which include flexible sigmoidoscopy (FSIG), colonoscopy (CSPY), double-contrast barium enema (DCBE), and computed tomographic colonography (CTC). Stool tests are best suited for the detection of cancer, although they also will deliver positive findings for some advanced adenomas, while the structural exams can achieve the dual goals of detecting adenocarcinoma as well as identifying adenomatous polyps.14Lieberman D.A. Weiss D.G. One-time screening for colorectal cancer with combined fecal occult-blood testing and examination of the distal colon.N Engl J Med. 2001; 345: 555-560Google Scholar These tests may be used alone or in combination to improve sensitivity or, in some instances, to ensure a complete examination of the colon if the initial test cannot be completed. Although screening tests for CRC vary in terms of the degree of supporting evidence, potential efficacy for incidence and mortality reduction, cost-effectiveness, and acceptability, any one of these options applied in a systematic program of regular screening has the potential to significantly reduce deaths from CRC. Beginning in 1980, the American Cancer Society (ACS) first issued formal guidelines for CRC screening in average-risk adults.15Eddy D. ACS report on the cancer-related health checkup.CA Cancer J Clin. 1980; 30: 193-240Google Scholar Since then, the ACS has periodically updated its CRC guidelines,16Levin B. Murphy G.P. Revision in American Cancer Society recommendations for the early detection of colorectal cancer.CA Cancer J Clin. 1992; 42: 296-299Google Scholar, 17Byers T. Levin B. Rothenberger D. et al.American Cancer Society guidelines for screening and surveillance for early detection of colorectal polyps and cancer: update 1997 American Cancer Society Detection and Treatment Advisory Group on Colorectal Cancer.CA Cancer J Clin. 1997; 47: 154-160Google Scholar, 18Smith R.A. von Eschenbach A.C. Wender R. et al.American Cancer Society guidelines for the early detection of cancer: update of early detection guidelines for prostate, colorectal, and endometrial cancers Also: update 2001—testing for early lung cancer detection.CA Cancer J Clin. 2001; 51: 38-75Google Scholar, 19Levin B. Brooks D. Smith R.A. Stone A. Emerging technologies in screening for colorectal cancer: CT colonography, immunochemical fecal occult blood tests, and stool screening using molecular markers.CA Cancer J Clin. 2003; 53: 44-55Google Scholar including adding recommendations for high-risk individuals in 1997.17Byers T. Levin B. Rothenberger D. et al.American Cancer Society guidelines for screening and surveillance for early detection of colorectal polyps and cancer: update 1997 American Cancer Society Detection and Treatment Advisory Group on Colorectal Cancer.CA Cancer J Clin. 1997; 47: 154-160Google Scholar Other organizations also have issued recommendations for CRC screening, most notably the US Preventive Services Task Force,20US Preventive Services Task ForceGuide to Clinical Preventive Services.2nd ed. Williams & Wilkins, Baltimore, MD1996Google Scholar, 21US Preventive Services Task ForceScreening for colorectal cancer: recommendation and rationale.Ann Intern Med. 2002; 137: 129-131Google Scholar the American College of Radiology (ACR),22Glick S.N. Comparison of colonoscopy and double-contrast barium enema.N Engl J Med. 2000; 343: 1728Google Scholar, 23Heiken J.P. Bree R.L. Foley W.D. et al.Colorectal cancer screening.American College of Radiology (ACR) Appropriateness Criteria. American College of Radiology, Reston, VA2006Google Scholar and the US Multi-Society Task Force on Colorectal Cancer (USMSTF).12Winawer S.J. Fletcher R.H. Miller L. et al.Colorectal cancer screening: clinical guidelines and rationale.Gastroenterology. 1997; 112: 594-642Abstract Full Text Full Text PDF Scopus (1815) Google Scholar, 24Winawer S. Fletcher R. Rex D. et al.Colorectal cancer screening and surveillance: clinical guidelines and rationale—update based on new evidence.Gastroenterology. 2003; 124: 544-560Google Scholar Recently, the ACS and the USMSTF collaborated on an update of earlier recommendations for postpolypectomy and post-CRC resection surveillance in response to reports suggesting significant deviation from existing recommendations.25Rex D.K. Kahi C.J. Levin B. et al.Guidelines for colonoscopy surveillance after cancer resection: a consensus update by the American Cancer Society and the US Multi-Society Task Force on Colorectal Cancer.Gastroenterology. 2006; 130: 1865-1871Google Scholar, 26Winawer S.J. Zauber A.G. Fletcher R.H. 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.CA Cancer J Clin. 2006; 56: 143-159Google Scholar Since 1997, the organizational guidelines for average-risk adults have grown increasingly similar and represent a broad organizational consensus on the value, options, and methods for periodic screening for CRC. In the last decade, there has been an increase in the number of technologies available for CRC screening, and in the case of stool tests, there has been growth in the number of commercial versions of guaiac-based and immunochemical-based stool tests (gFOBT and FIT). This growth in options also has been accompanied by changing patterns in the proportion of adults using different tests, with FSIG rates declining, CSPY rates increasing, use of stool blood tests remaining somewhat constant, and use of the DCBE for screening now becoming very uncommon.8Meissner H.I. Breen N. Klabunde C.N. Vernon S.W. Patterns of colorectal cancer screening uptake among men and women in the United States.Cancer Epidemiol Biomarkers Prev. 2006; 15: 389-394Google Scholar There are pros and cons to having a range of options for CRC screening. Despite the fact that the primary barriers to screening are lack of health insurance, lack of physician recommendation, and lack of awareness of the importance of CRC screening,27Wee C.C. McCarthy E.P. Phillips R.S. Factors associated with colon cancer screening: the role of patient factors and physician counseling.Prev Med. 2005; 41: 23-29Google Scholar the historical evidence shows that adults have different preferences and patterns of use among the available CRC screening tests.28Vernon S.W. Participation in colorectal cancer screening: a review.J Natl Cancer Inst. 1997; 89: 1406-1422Google Scholar, 29Schroy 3rd, P.C. Heeren T.C. Patient perceptions of stool-based DNA testing for colorectal cancer screening.Am J Prev Med. 2005; 28: 208-214Google Scholar, 30Tangka F.K. Molinari N.A. Chattopadhyay S.K. Seeff L.C. Market for colorectal cancer screening by endoscopy in the United States.Am J Prev Med. 2005; 29: 54-60Google Scholar, 31Lafata J.E. Divine G. Moon C. Williams L.K. Patient-physician colorectal cancer screening discussions and screening use.Am J Prev Med. 2006; 31: 202-209Google Scholar Although population preferences or resistance to a particular technology may change over time or may be influenced by referring physicians, it also may be true that over time some adults may persist in choosing one technology and rejecting another. Furthermore, at this time not all options are available to the entire population, and transportation, distance, and financial barriers to some screening technologies may endure for some time. Although in principle all adults should have access to the full range of options for CRC screening, the fact that simpler, lower-cost options are available in most settings, whereas other more costly options are not universally available, is a public health advantage. However, for average-risk adults, multiple testing options challenge the referring physician to support an office policy that can manage a broad range of testing choices, their follow-up requirements, and shared decision making related to the options. Shared decision making for multiple screening choices is both demanding and time consuming and is complicated by the different characteristics of the tests and the test-specific requirements for individuals undergoing screening.31Lafata J.E. Divine G. Moon C. Williams L.K. Patient-physician colorectal cancer screening discussions and screening use.Am J Prev Med. 2006; 31: 202-209Google Scholar In addition, the description of benefits is complicated by different performance characteristics of the variants of the occult blood tests and uncertain differences between test performance in research settings and test performance in clinical practice. These challenges have been discussed in the past,19Levin B. Brooks D. Smith R.A. Stone A. Emerging technologies in screening for colorectal cancer: CT colonography, immunochemical fecal occult blood tests, and stool screening using molecular markers.CA Cancer J Clin. 2003; 53: 44-55Google Scholar, 32Pignone M. Rich M. Teutsch S.M. et al.Screening for colorectal cancer in adults at average risk: a summary of the evidence for the US Preventive Services Task Force.Ann Intern Med. 2002; 137: 132-141Google Scholar and they still are with us today. In this guideline review, we have reassessed the individual test evidence and comparative evidence for stool tests, including gFOBT, FIT, and stool DNA test (sDNA), and the structural exams, including FSIG, CSPY, DCBE, and CTC, the latter also known as virtual colonoscopy. We have sought to address a number of concerns about the complexity of offering multiple screening options and the degree to which the range of screening options and their performance, costs, and demands on individuals poses a significant challenge for shared decisions. An overriding goal of this update is to provide a practical guideline for physicians to assist with informed decision making related to CRC screening. These guidelines are for individuals at average risk. Individuals with a personal or family history of CRC or adenomas, inflammatory bowel disease, or high-risk genetic syndromes should continue to follow the most recent recommendations for individuals at increased or high risk.24Winawer S. Fletcher R. Rex D. et al.Colorectal cancer screening and surveillance: clinical guidelines and rationale—update based on new evidence.Gastroenterology. 2003; 124: 544-560Google Scholar, 25Rex D.K. Kahi C.J. Levin B. et al.Guidelines for colonoscopy surveillance after cancer resection: a consensus update by the American Cancer Society and the US Multi-Society Task Force on Colorectal Cancer.Gastroenterology. 2006; 130: 1865-1871Google Scholar, 26Winawer S.J. Zauber A.G. Fletcher R.H. 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.CA Cancer J Clin. 2006; 56: 143-159Google Scholar The guidelines update process was divided into 2 phases. The first phase focused on the stool tests, including gFOBT, FIT, and sDNA. The second phase of the guidelines update process focused on the structural exams, including FSIG, colonoscopy, DCBE,and CTC. Deliberations about evidence and presentations from experts took place during 2 face-to-face meetings of the the collaborating organizations and invited outside experts and through periodic conference calls. The process relied on earlier evidence-based reviews.12Winawer S.J. Fletcher R.H. Miller L. et al.Colorectal cancer screening: clinical guidelines and rationale.Gastroenterology. 1997; 112: 594-642Abstract Full Text Full Text PDF Scopus (1815) Google Scholar, 16Levin B. Murphy G.P. Revision in American Cancer Society recommendations for the early detection of colorectal cancer.CA Cancer J Clin. 1992; 42: 296-299Google Scholar, 17Byers T. Levin B. Rothenberger D. et al.American Cancer Society guidelines for screening and surveillance for early detection of colorectal polyps and cancer: update 1997 American Cancer Society Detection and Treatment Advisory Group on Colorectal Cancer.CA Cancer J Clin. 1997; 47: 154-160Google Scholar, 18Smith R.A. von Eschenbach A.C. Wender R. et al.American Cancer Society guidelines for the early detection of cancer: update of early detection guidelines for prostate, colorectal, and endometrial cancers Also: update 2001—testing for early lung cancer detection.CA Cancer J Clin. 2001; 51: 38-75Google Scholar, 19Levin B. Brooks D. Smith R.A. Stone A. Emerging technologies in screening for colorectal cancer: CT colonography, immunochemical fecal occult blood tests, and stool screening using molecular markers.CA Cancer J Clin. 2003; 53: 44-55Google Scholar, 20US Preventive Services Task ForceGuide to Clinical Preventive Services.2nd ed. Williams & Wilkins, Baltimore, MD1996Google Scholar, 21US Preventive Services Task ForceScreening for colorectal cancer: recommendation and rationale.Ann Intern Med. 2002; 137: 129-131Google Scholar, 24Winawer S. Fletcher R. Rex D. et al.Colorectal cancer screening and surveillance: clinical guidelines and rationale—update based on new evidence.Gastroenterology. 2003; 124: 544-560Google Scholar Literature related to CRC screening and specific to individual tests published between January 2002 and March 2007 was identified using MEDLINE (National Library of Medicine) and bibliographies of identified articles. Expert panel members also provided several unpublished abstracts and manuscripts. Where evidence was insufficient or lacking to provide a clear, evidence-based conclusion, final recommendations were based on expert opinion and are so indicated. While there is clear experimental evidence that screening for CRC with gFOBT is associ-ated with reduced incidence and mortality from CRC screening,5Hardcastle J.D. Chamberlain J.O. Robinson M.H. et al.Randomised controlled trial of faecal-occultblood screening for colorectal cancer.Lancet. 1996; 348: 1472-1477Google Scholar, 6Kronborg O. Fenger C. Olsen J. et al.Randomised study of screening for colorectal cancer with faecaloccult- blood test.Lancet. 1996; 348: 1467-1471Google Scholar, 33Mandel J.S. Bond J.H. Church T.R. et al.Reducing mortality from colorectal cancer by screening for fecal occult blood Minnesota Colon Cancer Control Study.N Engl J Med. 1993; 328: 1365-1371Google Scholar most of the information supporting the use of the other colorectal screening tests is based on observational and inferential evidence. In this review, priority was placed on studies of asymptomatic average-risk or higher-risk populations that were followed by testing with colonoscopy in all or nearly all study participants as a validation measure. In this update of guidelines for CRC screening in average-risk adults, the expert panel concluded that a screening test must be able to detect the majority of prevalent or incident cancers at the time of testing. Here we are drawing a new, important distinction between test sensitivity and program sensitivity, the former being the sensitivity achieved in a single test and the latter being the sensitivity achieved over time through serial testing in a program. While cancer screening tests are expected to achieve acceptable levels of sensitivity and specificity,34Wilson J.M.G. Junger G. Principles and Practice of Screening for Disease. World Health Organization, Geneva, Switzerland1968Google Scholar no specific acceptance threshold for either measure, alone or in combination, has been established for any screening test.35Smith R.A. Screening fundamentals.J Natl Cancer Inst Monogr. 1997; 22: 15-19Google Scholar, 36Shapiro SScreening for secondary prevention of disease, in Armenian HK, Shapiro S (eds).Epidemiology and Health Services.1831998194Oxford University PressNew York, NY 206.Google Scholar Thus, this criterion is based on expert opinion and the following considerations. First, in the judgment of the panel, recent evidence has revealed an unacceptably wide range of sensitivity among some gFOBT strategies, with some practices and tests performing so poorly that the large majority of prevalent cancers are missed at the time of screening.37Imperiale T.F. Ransohoff D.F. Itzkowitz S.H. et al.Fecal DNA versus fecal occult blood for colorectal- cancer screening in an average-risk population.N Engl J Med. 2004; 351: 2704-2714Google Scholar, 38Collins J.F. Lieberman D.A. Durbin T.E. Weiss D.G. Accuracy of screening for fecal occult blood on a single stool sample obtained by digital rectal examination: a comparison with recommended sampling practice.Ann Intern Med. 2005; 142: 81-85Google Scholar, 39Nadel M.R. Shapiro J.A. Klabunde C.N. et al.A national survey of primary care physicians' methods for screening for fecal occult blood.Ann Intern Med. 2005; 142: 86-94Google Scholar The observation of very low sensitivity for cancer and advanced neoplasia associated with in-office gFOBT led Sox to speculate that CRC mortality rates might be considerably lower today if the quality of gFOBT testing during the previous decade had been higher.40Sox H.C. Office-based testing for fecal occult blood: do only in case of emergency.Ann Intern Med. 2005; 142: 146-148Google Scholar While the literature on other CRC screening tests also reveals a range of sensitivities, even in the presence of significant, correctable, quality-related shortcomings, the majority of invasive cancers still will be detected. Second, a test like gFOBT that demonstrates poor test sensitivity but good program sensitivity depends on high rates of adherence with regular screening. However, many patients have only one test and do not return the following year for programmatic testing.41Myers R.E. Balshem A.M. Wolf T.A. et al.Adherence to continuous screening for colorectal neoplasia.Med Care. 1993; 31: 508-519Google Scholar, 42Engelman K.K. Ellerbeck E.F. Ahluwalia J.S. et al.Fecal occult blood test use by Kansas medicare beneficiaries.Prev Med. 2001; 33: 622-626Google Scholar Given the lack of systems to ensure or at least facilitate adherence with recommended regular screening intervals, as well as evidence of suboptimal awareness and engagement of primary care in supporting adherence with screening recommendations,43Schattner A. Gilad A. Primary care physicians' awareness and implementation of screening guidelines for colorectal cancer.Prev Med. 2002; 35: 447-452Google Scholar the panel concluded that it was not realistic at this time to rely on program sensitivity to overcome limitations in test sensitivity. Physicians and institutions should select stool blood tests that have been shown in the scientific literature to detect the majority of prevalent CRCs in an asymptomatic population. If there is not evidence that an available test has met that benchmark, it should not be offered to patients for CRC screening. Individuals and health care professionals should also understand that screening tests for CRC broadly fall into 2 categories. In one category are the fecal tests (ie, gFOBT, FIT, and sDNA), which are tests that primarily are effective at identifying CRC. Some premalignant adenomatous polyps may be detected, providing an opportunity for polypectomy and the prevention of CRC, but the opportunity for prevention is both limited and incidental and is not the primary goal of CRC screening with these tests. In the second category are the partial or full structural exams (ie, FSIG, CSPY, DCBE, and CTC)44American College of Radiology Imaging NetworkACRIN Protocol 6656 Computerized Tomographic Colonography: Performance Evaluation in a Multicenter Setting.http://www.acrin.org/TabID/146/Default.aspxDate: 2007Google Scholar which are tests that are effective at detecting cancer and premalignant adenomatous polyps. These tests differ in complexity and accuracy for the detection of CRC and advanced neoplasia. When performed properly, each of these structural exams has met the standard of detecting at least half of prevalent or incident cancers at the time of testing. It is the strong opinion of this expert panel that colon cancer prevention should be the primary goal of CRC screening. Tests that are designed to detect both early cancer and adenomatous polyps should be encouraged if resources are available and patients are willing to undergo an invasive test. These tests include the partial or full structural exams mentioned above. These tests require bowel preparation and an office or hospital visit and have various levels of risk to patients. These tests also have limitations, greater patient requirements for successful completion, and potential harms. Significant positive findings on FSIG, DCBE, and CTC require follow-up CSPY. The panel recognized that some patients will not want to undergo an invasive test that requires bowel preparation, may prefer to have screening in the privacy of their home, or may not have access to the invasive tests due to lack of coverage or local resources. Collection of fecal samples for blood or DNA testing can be performed at home without bowel preparation. However, providers and patients should understand the following limitations and requirements of noninvasive tests:•These tests are less likely to prevent cancer compared with the invasive tests;•These tests must be repeated at regular intervals to be effective;•If the test is abnormal, an invasive test (CSPY) will be needed. If patients are not willing to have repeated testing or have CSPY if the test is abnormal, these programs will not be effective and should not be recommended. Based on our review of the historic and recent evidence, the tests in Table 1 are acceptable options for the early detection of CRC and adenomatous polyps for asymptomatic adults aged 50 years and older (also see Table 2).Table 1Testing Options for the Early Detection of Colorectal Cancer and Adenomatous Polyps for Asymptomatic Adults Aged 50 Years and OlderTests that detect adenomatous polyps and cancer FSIG every 5 years, or CSPY every 10 years, or DCBE every 5 years, or CTC every 5 yearsTests that primarily detect cancer Annual gFOBT with high test sensitivity for cancer, or Annual FIT with high test sensitivity for cancer, or sDNA, with high sensitivity for cancer, interval uncertain Open table in a new tab Table 2Guidelines for Screening for the Early Detection of Colorectal Cancer and Adenomas for Average-risk Wo