American Society For Gastrointestinal Endoscopy

Guidelines for Colorectal Cancer Screening and Surveillance Colorectal cancer (CRC) is the third most commonly diagnosed cancer and the second leading cause of cancer-related death in the U.S.1 Each year, approximately 130,000 individuals are diagnosed and over 50,000 will die from this malignancy1. The 5-year survival rate for early stage cancers is over 90%, while the 5-year rate for those diagnosed with wide spread cancer is less than 10%. Indirect evidence suggests that most cancers develop from adenomatous polyps and that it takes on average 10 years for a < 1 cm polyp to transform into invasive CRC 2,3. Given the finding that colon polyps and early cancers are usually asymptomatic and the abovementioned dwell time between polyp and cancer, there appears to be a significant opportunity for CRC prevention by screening asymptomatic individuals. Only 30% of individuals harbor risk factors for colorectal cancer 4. These risk factors include family history of colorectal cancer, a personal history of colon polyps or cancer, a personal history of inflammatory bowel disease, and the familial polyposis syndromes (including familial adenomatous polyposis [FAP], hereditary nonpolyposis colon cancer [HNPCC]). The other 70% of individuals are considered average risk. There has been mounting evidence regarding the efficacy of screening average risk individuals for CRC. Prospective randomized trials of fecal occult blood testing (FOBT) have demonstrated a 15-33% reduction in CRC-related mortality5,6,7. Case -control studies (mostly utilizing rigid sigmoidoscopes) have suggested a reduction in CRC-related mortality between 59-80% 8,9,10 in the portion of the colon examined. It has been estimated that the overall reduction in CRC-related mortality from flexible sigmoidoscopy screening up until age 80 would be ASGE Publication No. 1014 Published 2000 *Request for reprints of these itmes and this statement should be addressed to: American Society for Gastrointestinal Endoscopy 13 Elm Street Manchester, MA 01944-1314 www.asge.org [email protected] VOLUME 51, NO. 6, 2000

approximately 45%11. As yet there are no published prospective trials of screening flexible sigmoidoscopy showing a diminution in CRC -related mortality. These studies have prompted several groups to publish new guidelines for CRC screening. The American Cancer Society (ACS), the United States Preventive Service Task Force, and a consortium including the American Society for Gastrointestinal Endoscopy, American Gastroenterology Association, American College of Gastroenterology, American Society of Colon and Rectal Surgeons, Society of American Gastrointestinal Endoscopy Surgeons, initially supported by the Agency for Health Care Policy and Research (AHCPR), have all published guidelines within the past 5 years regarding CRC screening and surveillance recommendations12,13,14. SCREENING FOR AVERAGE RISK INDIVIDUALS Fecal Occult Blood Testing. All three groups agree that individuals at average risk for CRC should begin yearly fecal occult blood testing at age 50. The recommended method includes the patient eating a meat-free diet one day prior to stool collection. Three fecal occult blood test slides with two windows each, should be completed by the patient. Samples obtained by digital rectal exam (DRE) and/or which include hydration have higher false positive rates. Patients with a positive FOBT have an increased risk of advanced neoplasia and should undergo a complete examination of the colon and rectum by colonoscopy. An alternative is double contrast barium enema (DCBE) and flexible sigmoidoscopy, although a total colonoscopic exam is preferred because of its superior diagnostic characteristics 15 and the ability to remove detected lesions. FLEXIBLE SIGMOIDOSCOPY The above mentioned case-control studies have prompted guidelines recommending the utilization of flexible sigmoidoscopy as part of a CRC screening program. The ACS and the consortium recommend this procedure every 5 years starting at age 50 for average risk individuals. The United States Preventive Services Task Force also recommends this procedure but does not specify an appropriate GASTROINTESTINAL ENDOSCOPY

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Table 1. Alternatives for CRC Screening in Average Risk Individuals (beginning at age 50) Fecal occult blood testing -yearly Flexible sigmoidoscopy- every 5 years FOBT yearly/flexible sigmoidoscopy every 5 years Double contrast barium enema (with FS) - every 5 years Colonoscopy- every 10 years

interval. Individuals with a polyp or polyps > 1 cm should undergo complete colon evaluation, with colonoscopy. There remains considerable controversy regarding whether individuals with adenomatous polyps less than 1 cm should undergo colonoscopy16,17,18,19. There is limited evidence that combining yearly FOBT and flexible sigmoidoscopy every 5 years results in better long-term survival if cancers are detected 20. DOUBLE CONTRAST BARIUM ENEMA The ACS and the consortium have endorsed DCBE every 5-10 years as an alternative for screening average risk individuals. However, at this time, there are no prospective studies demonstrating the efficacy of DCBE for reducing CRC-related mortality through screening. The addition of flexible sigmoidoscopy with DCBE should be considered due to the poor visualization of the rectosigmoid colon by DCBE alone. While DCBE offers evaluation of the entire colon, its diagnostic sensitivity is inferior to colonoscopy and it lacks therapeutic capability. A recent, prospective study found that the sensitivity for detecting CRC was 83% for barium enema radiography versus 95% for colonoscopy 21. COLONOSCOPY Both the consortium and the ACS recommend colonoscopy every 10 years as an alternative for CRC screening. Colonoscopy offers the advantages of complete visualization of the entire colon and therapeutic potential. Currently, there are no direct studies evaluating whether screening colonoscopy alone reduces CRC-related mortality. There is indirect evidence from the FOBT trials that colonoscopy reduces CRC-related mortality 5,6,7. However, the performance of colonoscopy is similar to sigmoidoscopy and there is direct evidence that sigmoidoscopy is effective in reducing CRC-related mortality. The choice of modality for CRC screening should be discussed between practitioner and patient. HIGH RISK GROUPS Colonoscopy for cancer surveillance is appropriate in certain high-risk patients. Risk factors for colon 778

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cancer include longstanding ulcerative colitis, Crohn’s colitis, familial cancer syndromes, and personal history of colorectal neoplastic polyps or cancer. PERSONAL HISTORY OF INFLAMMATORY BOWEL DISEASE Individuals with longstanding ulcerative colitis or Crohn’s colitis (pancolitis for 8 or more years or, left-sided colitis for 15 or more years) may undergo colonoscopic surveillance with systematic biopsies every 1-3 years22,23 although there is no direct evidence supporting this practice. The role of colonoscopy in the management of patients with inflammatory bowel disease is discussed in another guideline24. The majority of polyps found in ulcerative colitis (UC) are inflammatory in nature. However, the finding of an adenomatous polyp in an individual with UC poses a clinical dilemma. Adenomas are, by definition, mass lesions with dysplasia. Adenomas located outside of the segment of UC may be managed the same as adenomas found in patients without UC. For adenomas found within a UC segment, limited available data suggest that, in the absence of dysplasia in the surrounding mucosa, these polyps may be managed similarly to polyps in individuals without UC25,26. The risk of malignancy appears to be low if no dysplasia is seen in these biopsies. Further studies are needed to clarify this controversial issue. POLYPOSIS SYNDROMES Individuals with a family history of familial adenomatous polyposis (FAP) or Gardner’s syndrome should undergo genetic testing with counseling and annual flexible sigmoidoscopy beginning at age 10 to 12 years; colectomy should be recommended when polyposis is found27,28. Affected individuals have nearly a 100% risk of developing colorectal cancer by the age of 40. They should be counseled regarding colectomy. If no polyps are seen, then annual sigmoidoscopy should be offered to age 40 and then every 3-5 years thereafter. Colonoscopic surveillance is not effective in preventing colon cancer in this setting. Hereditary nonpolyposis colorectal cancer (HNPCC) should be suspected in patients with several relatives with CRC, especially if one or more of the relatives developed CRC before age 50. Genetic counseling and testing should be considered in these patients. Colonoscopic surveillance has been recommended every 2 years starting at age 25 or 5 years younger than the earliest diagnosis of CRC, whichever is earlier. Annual screening should be performed yearly after age 4029. However, there is VOLUME 51, NO. 6, 2000

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Table 2. Screening recommendations for individuals with significant family history Family History

Screening Recommendation

FAP with positive genetic test proband

Offer genetic testing with counseling; if positive, annual FS beginning at age 10-12 years with colectomy when polyps develop. If no polyps annual FS to age 40, then every 3-5 years after. FS in all potentially affected relatives as performed above. Colonoscopy every 2 years beginning at age 25, or 5 years younger than the earliest age of diagnosis of CRC, whichever is earlier. Annual screening after age 40. Colonoscopy every 3-5 years beginning at an age 10 years younger than the age at diagnosis of the youngest affected relative.

FAP with negative genetic test proband HNPCC First degree relatives with sporadic CRC or adenomas prior to age 60 or multiple first degree relatives with CRC or adenomas

no direct evidence regarding the appropriate interval of surveillance in these patients.

Table 3. Surveillance recommendations for individuals with significant personal history

FAMILY HISTORY OF CRC/POLYPS Individuals with a family history of CRC or adenomas (other than FAP and HNPCC) are also at increased risk30 for the development of CRC compared to the general population. It is recommended that individuals with a first-degree relative diagnosed with sporadic CRC or adenomas before the age of 60 or with multiple first-degree relatives diagnosed with CRC or adenomas undergo colonoscopic screening. Colonoscopy is recommended every 3-5 years beginning at an age 10 years younger than the age of the youngest affected relative19. There is no direct evidence regarding the initiation or appropriate interval of surveillance in these patients.

Personal History

PERSONAL HISTORY OF COLORECTAL CANCER Patients with a personal history of colorectal cancer are at increased risk for a metachronous cancer as well as at risk for recurrence of the index cancer. These individuals should undergo a preoperative colonoscopic examination if possible. If this is not feasible, a complete postoperative examination should be performed within 1 year of resection. If either of these examinations is normal, then a subsequent examination may be performed at 3-6 years.

tial follow-up examination. Most experts recommend that surveillance intervals be tailored according to the type of polyps removed on colonoscopy. Individuals with high risk lesions such as polyps that are ≥1 cm and/or have villous architecture should have more frequent surveillance than individuals with small, tubular adenomas. These intervals should be individualized.

PERSONAL HISTORY OF ADENOMAS Colonoscopy is the preferred method of postpolypectomy follow-up. In addition to being the most sensitive method of polyp detection, it permits the removal of most recurrent polyps. The optimal interval for follow-up colonoscopy after clearance of the colon appears to be 3 years. The National Polyp Study found that patients randomized to undergo post-polypectomy surveillance at 1 and 3 years versus 3 years only showed no difference in the frequency of detection of polyps with advanced pathology31. The recommended interval for subsequent colonoscopic surveillance depends upon the number and type of polyps seen on the iniVOLUME 51, NO. 6, 2000

Prior CRC

Prior colonic adenomas

Surveillance Recommendation Clearance of the remainder of the colon at or around the time of resection, followed by colonoscopy at 3 years after curative resection, then at 3-6 year intervals to detect metachronous neoplasia. After adequate clearance, surveillance colonoscopy at 3-6 year intervals.

Ulcerative Surveillance colonoscopy every 1-3 years pancolitis / with systematic biopsies to detect Crohn’s pancolitis dysplasia. of 8 years’ duration Left sided colitis of > 15 years’ duration

MANAGEMENT OF POLYPS Most polyps seen during colonoscopy can be completely removed by electrocautery. The safety of this procedure has been substantiated by the low incidence of complications reported in numerous series 32,33,34,35. The endoscopist should always be prepared to perform a total examination and remove all polyps found at the time of the first colonoscopy, although technical factors encountered during colonoscopy may limit completion of the procedure. Every effort should be made to avoid repetitive procedures. The finding of a neoplastic polyp > 1 cm by rigid or flexible sigmoidoscopy is an indication for examination of the entire colon, since 30-50% of such patients will harbor additional polyps. Controversy GASTROINTESTINAL ENDOSCOPY

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remains over whether colonoscopy is indicated in patients with polyp(s) < 1 cm found on sigmoidoscopy. A Mayo Clinic study showed that patients with distal polyps < 1 cm were at no greater cancer risk than the general population36. However, these polyps were fulgurated, so their histology was unknown. A study from St. Marks Hospital in London found no increased cancer risk in individuals with a single < 1 cm tubular adenoma37. A recent Lahey Clinic study found advanced neoplasms (size > 1 cm and/or tubulovillous or carcinomatous histology) in 6% of those with diminutive (1-5 mm) and 10% of individuals with small (6-10 mm) distal polyps38. A fourth study found that individuals with a single distal diminutive tubular adenoma had a low prevalence of advanced proximal polyps (0%; 95% CI, 0-4%)39. Because the aforementioned data are conflicting and the various study designs potentially flawed, the decisions to perform colonoscopy on these patients should be individualized. Biopsy-proven inflammatory colorectal polyps are not related to cancer40. It is not clear whether individuals with hyperplastic polyps have an associated incidence of adenomatous polyps higher than that of control subjects without hyperplastic polyps. Colonoscopy is the preferred method of examination of the colon following a flexible sigmoidoscopy with at least one tubular adenoma because it allows both detection and removal of synchronous polyps. The morbidity, mortality and cost of colonoscopic polypectomy are significantly less than those for polypectomy by laparotomy41. The latter is justified only when an experienced endoscopist is unable to remove the entire lesion safely. Although controversy still exists regarding the degree of malignant potential of polypoid lesions of the colon, current opinion is that most cancers arise in preexisting neoplastic polyps42. It is impossible to tell grossly which lesions are or will become malignant. The incidence of malignancy in a polyp rises as the size and villous component of the polyp increase43. Because malignant changes in polyps are frequently missed by single and even multiple forceps biopsies, histologic evaluation should be based on examination of the completely excised polyp. In general, all polypoid lesions greater than 1 cm in diameter should be totally excised and recovered for histologic examination. The decision to perform colonoscopy for the purpose of removing polyps less than 1 cm in diameter is controversial and should be individualized. Depending on the patient’s age, past history, family history and the presence of other diseases, colonoscopic polypectomy may be recommended for removal of these small lesions. Although occur-

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rence of carcinoma in a lesion under 0.5 cm is rare, it is reasonable to destroy or remove all such diminutive lesions as they are encountered at the time of colonoscopy for any indication. Representative biopsy samples may be obtained when these lesions are too numerous for all of them to be removed. Large sessile polyps have a high malignant potential and tend to have microscopic foci of residual polyp after excision44. Therefore, a patient who has colonoscopic excision of these lesions should have repeat evaluation of the polyp site within 6 months to document complete removal. If residual polyp tissue is found, it should be removed if possible and the completeness of excision checked once again within another 6-month period. If complete removal of the lesion has been verified at the first or second follow-up interval, then subsequent surveillance colonoscopy should be individualized. If, however, a large benign-appearing sessile polyp cannot be completely or safely removed endoscopically within 1-3 examinations, then subsequent bowel resection is indicated. Patients with adenomatous polyps exhibiting severe dysplasia or carcinoma superficial to the muscularis mucosae can be followed after polypectomy in the same manner as patients with polyps without these features45,46. The management of patients with pedunculated adenomas exhibiting carcinoma extending through the muscularis mucosae (invasive carcinoma) is controversial and must be individualized depending upon the operative risk category of the patient. The risk of lymph node spread is less than the risk of colonic surgery in most patients with malignant, pedunculated polyps provided that the polyp has been completely resected completely, and adequately processed, and there is no histologic evidence of high-grade carcinoma, vascular or lymphatic invasion, or involvement of the margin of the resection. Resection of the involved segment of the colon is recommended when these criteria are not met and may also be justified in selected younger, good-risk patients. Patients with a sessile polyp in which carcinoma has penetrated the muscularis mucosae should usually undergo surgical resection unless contraindicated by the condition of the patient47,48. REFERENCES 1. Parker SL, Tong T, Bolden S, Wingo PA. Cancer Statistics, 1997. CA Cancer J Clin 1997;47:5-27. 2. Stryker SJ, Wolff BG, Culp CE, et al. Natural history of untreated colonic polyps. Gastroenterology 1987;93:1009-13. 3. Morson BC. The evolution of colorectal carcinoma. Clin Radiol 1984;35:425-31. 4. Winawer SJ, Fletcher RH, Miller RH, et al. Colorectal cancer

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screening: clinical guidelines and rationale. Gastroenterology 1997; 112:594-642. Mandel JS, Bond JH, Church TS, et al. Reducing mortality from colorectal cancer by screening for fecal occult blood. Minnesota Colon Cancer Control Study. N Eng J Med 1993; 328:1365-71. Kronborg O, Fenger C, Olsen J, et al. Randomised study of screening for colorectal cancer with faecal-occult-blood test. Lancet 1996;348:1467-71. Hardcastle JD, Chamberlain JO, Robinson MH, et al. Randomised controlled trial of faecal-occult-blood screening for colorectal cancer. Lancet 1996;348:1472-77. Newcomb PA, Norfleet RG, Storer BE, et al. Screening sigmoidoscopy and colorectal cancer mortality. J Natl Cancer Inst 1992;84:1572-75. Selby JV, Friedman GD, Quisenberry CP, Weiss N Jr. A casecontrol study of screening sigmoidoscopy and mortality from colorectal cancer. N Engl J Med 1992;326:653-7. Muller AD, Sonnenberg A. Protection by endoscopy against death from colorectal cancer. A case-control study among veterans. Arch Int Med 1995;155:1741-8. Atkin WS, Cuzick J, Northover JMA, Whynes DK. Prevention of colorectal cancer by once-only sigmoidoscopy. The Lancet 1993; 341:736-40. Byers 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. Ca Cancer J Clin 1997;47:154-60. Guide to clinical preventive services. 2nd ed. Report to the U.S. Preventive Services Task Force. Washington, D.C.: Department of Health and Human Services, 1995. Winawer SJ, Fletcher RH, Miller RH, et al. Colorectal cancer screening: clinical guidelines and rationale. Gastroenterology 1997; 112:594-642. Johnson CD, Ilstrup DM, Fish NM, et al. Barium enema and colon cancer screening: finally a study. AJR 1997;167:39-43. Spencer RJ, Melton LJ III, Ready RL. Treatment of small colorectal polyps: a population-based study of the risk of subsequent carcinoma. Mayo Clin Proc 1984;59:305-10. Atkin WS, Morson BC, Cuzick J. Long-term risk of colorectal cancer after excision of rectosigmoid adenomas. NEJM 1992; 326:658-62. Read T, Read J, Butterly L. Importance of adenomas 5 mm or less in diameter that are detected by sigmoidoscopy, NEJM 1997;336:8-12. Wallace MB, Kemp JA, Trnka YM, et al. Is colonoscopy indicated for small adenomas found by screening flexible sigmoidoscopy? Ann Int Med 1998;129:273-8. Winawer SJ, Flehinger BJ, Schottenfeld D, Miller DG. Screening for colorectal cancer with fecal occult blood testing and sigmoidoscopy. J Natl Cancer Inst 1993;85:1311-8. Rex D, Rahmani E, Hasemann J, et al. Relative sensitivity of colonoscopy and barium enema for detection of colorectal cancer in clinical practice. Gastroenterology 1997;112:17-23. Ibid 14. Colonoscopy in the screening and surveillance of individuals at increased risk for colorectal cancer. Gastrointest Endosc 1998;48(6):676-8. The role of colonoscopy in the management of patients with inflammatory bowel disease. Gastrointest Endosc 1988 MayJun;34(3 Suppl):6S-7S. Connell WR, Lennard-Jones JE, Williams CB, et al. factors affecting outcome of endoscopic surveillance for cancer in ulcerative colitis. Gastroenterology 1994;107:934-44.

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26. Medlicott S, Jewell L, Price L et al. Conservative management of small adenomas in ulcerative colitis. Am J Gastroenterol 1997;92(11):2094-7. 27. Rhodes M, Bradburn DM. Overview of screening and management of familial adenomatous polyposis. Gut 1992;33:125-8. 28. Burt RW, Petersen GM. Familial colorectal cancer: diagnosis and management. In Young GP, Rozen P, Levin B (eds) Prevention and early detection of colorectal cancer ,171193.Philadelphia,PA 1997 29. Jarvininen DG, Mecklin JP, Sistonen P. Screening reduces colorectal cancer rate in families with hereditary nonpolyposis colorectal cancer. Gastroenterology 1995;108:1405-11. 30. Levin B, Murphy GP. Revision in American Cancer Society recommendations for the early detection of colorectal cancer. CA Cancer J Clin 1992;42:296-9. 31.Winawer SJ, Zauber AG, O’Brien MJ, et al. Randomized comparison of surveillance intervals after colonoscopic removal of newly diagnosed polyps. NEJM 1993;328:901-6. 32. Rogers BH, Silvis SE, Nebel OT. Complications of flexible fiberoptic colonscopy and polypectomy: an analysis of the ASGE survey. Gastrointest Endosc 1975;22:73-7. 33. Macrae FA, Tan KG, Williams CB. Towards safer colonoscopy: a report on complications of 5000 colonoscopies. Gut 1983;24:376-83. 34. Waye JD, Lewis BS, Yessayan S. Colonoscopy: A prospective report of complications. J Clin Gastro 1992;15(4):347-51. 35. Vernava AM, Longo WE. Complications of endoscopic polypectomy. Surg OncClin N Am 1996;5(3):663-73. 36. Spencer RJ, Melton LJ III, Ready RL. Treatment of small colorectal polyps: a population-based study of the risk of subsequent carcinoma. Mayo Clin Proc 1984;59:305-10. 37. Atkin WS, Morson BC, Cuzick J. Long-term risk of colorectal cancer after excision of rectosigmoid adenomas. NEJM 1992;326:658-62. 38. Read T, Read J, Butterly L. Importance of adenomas 5 mm or less in diameter that are detected by sigmoidoscopy, NEJM 1997;336:8-12. 39. Wallace MB, Kemp JA, Trnka YM, et al. Is colonoscopy indicated for small adenomas found by screening flexible sigmoidoscopy? Ann Int Med 1998;129:273-8. 40. Muto T, Bussey HFT, Morson BC. The evolution of cancer of the colon and rectum. Cancer 1975;36:2251-8. 41. Shinya H, Wolff WI. Morphology, anatomic distribution and cancer potential of colonic polyps: an analysis of 7000 polyps endoscopically removed. Ann Surg 1979;109:679-85. 42. Morson BC, Koishi F. Dysplasia in the colorectum. Clinics Gastroenterol 1980;supp 1:331-9. 43. Muto T, Ishikawa K, Kino I, et al. Comparative histological study of adenomas of the large intestine in Japan and England, with special reference to malignant potential. Dis Col Rectum 1977;20:11-9. 44. Ibid. 45. Fenoglio-Preiser CM, Hutter RVP. Colorectal polyps: patologic diagnosis and clinical significance. CA 1985;35:322-59. 46. Witt TR, Winawer SJ. Cancer in a colonic polyp, or malignant colonic adenomas: is polypectomy sufficient? Gastroenterology 1981;81:625-32. 47. Cranley JP, Petras RE, Carey WD, et al. When is endoscopic polypectomy adequate therapy for colonic polyps containing invasive carcinoma? Gastroenterology 1986;91:419-25. 48. Morson BC, Whiteway JE, Jones EA, et al. Histopathology and prognosis of malignant colorectal polyps treated by colonic polypectomy. Gut 1984;25:437-44.

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Standards of Practice Committee Glenn M. Eisen, MD, Chair Robynne Chutkan, MD Jay L. Goldstein, MD Bret T. Petersen, MD Michael E. Ryan, MD Stuart Sherman, MD John Vargo, II, MD Richard A. Wright, MD Harvey S. Young, MD Marc F. Catalano, MD Virginia Walter, MS, RN, BS, CGRN

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