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Clinical Guidelines |

Screening for Colorectal Cancer: Recommendation and Rationale FREE

U.S. Preventive Services Task Force*
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From the U.S. Preventive Services Task Force, Agency for Healthcare Research and Quality, Rockville, Maryland.


Copyright ©2004 by the American College of Physicians


Ann Intern Med. 2002;137(2):129-131. doi:10.7326/0003-4819-137-2-200207160-00014
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This statement summarizes the current U.S. Preventive Services Task Force (USPSTF) recommendation on screening for colorectal cancer and the supporting scientific evidence and updates the 1995 recommendations contained in the Guide to Clinical Preventive Services, 2nd edition. At that time, the USPSTF recommended screening for colorectal cancer with annual fecal occult blood testing, periodic sigmoidoscopy, or the combination of fecal occult blood testing and sigmoidoscopy but concluded that the evidence was insufficient to recommend for or against colonoscopy or barium enema.

The complete USPSTF recommendation and rationale statement on this topic, which includes a brief review of the supporting evidence, is available through the USPSTF Web site (http://www.preventiveservices.ahrq.gov), the National Guideline Clearinghouse (http://www.guideline.gov), and in print through the Agency for Healthcare Research and Quality Publications Clearinghouse (telephone, 800-358-9295; e-mail, ahrqpubs@ahrq.gov). The complete information on which this statement is based, including tables and references, is available in the accompanying article in this issue and in the summary of the evidence and systematic evidence review on the Web sites already mentioned.

*For a list of the members of the U.S. Preventive Services Task Force, see the Appendix.

The U.S. Preventive Services Task Force (USPSTF) strongly recommends that clinicians screen all men and women 50 years of age or older for colorectal cancer. This is a grade A recommendation. (See Appendix Table 1 for a description of the USPSTF classification of recommendations.)

The USPSTF found fair to good evidence that several screening methods are effective in reducing mortality from colorectal cancer. The USPSTF concluded that the benefits from screening substantially outweigh potential harms, but the quality of evidence, magnitude of benefit, and potential harms vary with each method.

The USPSTF found good evidence that periodic fecal occult blood testing (FOBT) reduces mortality from colorectal cancer and fair evidence that sigmoidoscopy alone or in combination with FOBT reduces mortality. The USPSTF did not find direct evidence that screening colonoscopy is effective in reducing colorectal cancer mortality rates; efficacy of colonoscopy is supported by its integral role in trials of FOBT, extrapolation from sigmoidoscopy studies, limited case–control evidence, and the ability of colonoscopy to inspect the proximal colon. Double-contrast barium enema offers an alternative means of whole-bowel examination, but it is less sensitive than colonoscopy and there is no direct evidence that it is effective in reducing mortality rates. The USPSTF found insufficient evidence that newer screening techniques (for example, computed tomographic colography) are effective in improving health outcomes. (See Appendix Table 2 for a description of the USPSTF classification of levels of evidence.)

There are insufficient data to determine which screening strategy is best in terms of the balance of benefits and potential harms or cost-effectiveness. Studies reviewed by the USPSTF indicate that colorectal cancer screening is likely to be cost-effective (<$30 000 per additional year of life gained) regardless of the strategy chosen.

It is unclear whether the increased accuracy of colonoscopy compared with alternative screening methods (for example, the identification of lesions that FOBT and flexible sigmoidoscopy would not detect) offsets the procedure's additional complications, inconvenience, and costs.

Potential screening options for colorectal cancer include home FOBT, flexible sigmoidoscopy, the combination of home FOBT and flexible sigmoidoscopy, colonoscopy, and double-contrast barium enema. Each option has advantages and disadvantages that may vary for individual patients and practice settings. The choice of specific screening strategy should be based on patient preferences, medical contraindications, patient adherence, and available resources for testing and follow-up. Clinicians should talk to patients about the benefits and potential harms associated with each option before selecting a screening strategy.

The optimal interval for screening depends on the test. Annual FOBT offers greater reductions in mortality rates than biennial screening but produces more false-positive results. A 10-year interval has been recommended for colonoscopy on the basis of evidence regarding the natural history of adenomatous polyps. Shorter intervals (5 years) have been recommended for flexible sigmoidoscopy and double-contrast barium enema because of the lower sensitivity of these methods, but there is no direct evidence with which to determine the optimal interval for tests other than FOBT. Case–control studies have suggested that sigmoidoscopy every 10 years may be as effective as sigmoidoscopy performed at shorter intervals.

The USPSTF recommends initiating screening at 50 years of age for men and women at average risk for colorectal cancer, based on the incidence of cancer above this age in the general population. In persons at higher risk (for example, those with a first-degree relative who receives a diagnosis of colorectal cancer before 60 years of age), initiating screening at an earlier age is reasonable.

Expert guidelines exist for screening very high-risk patients, including those with a history suggestive of familial polyposis or hereditary nonpolyposis colorectal cancer or those with a personal history of ulcerative colitis (1). Early screening with colonoscopy may be appropriate, and genetic counseling or testing may be indicated for patients with genetic syndromes.

The appropriate age at which colorectal cancer screening should be discontinued is not known. Screening studies have generally been restricted to patients younger than 80 years of age, with colorectal cancer mortality rates beginning to decrease within 5 years of initiating screening. Yield of screening should increase in older persons (because of higher incidence of colorectal cancer), but benefits may be limited as a result of competing causes of death. Discontinuing screening is therefore reasonable in patients whose age or comorbid conditions limit life expectancy.

Proven methods of FOBT screening use guaiac-based test cards that patients prepare at home from three consecutive stool samples and forward to the clinician. Whether patients need to restrict their diet and avoid certain medications is not established. Rehydration of the specimens before testing increases the sensitivity of FOBT but substantially increases the number of false-positive results. Neither digital rectal examination nor the testing of a single stool specimen obtained during digital rectal examination is recommended as an adequate screening strategy for colorectal cancer.

The combination of FOBT and sigmoidoscopy may detect more cases of cancer and more large polyps than either test alone, but the additional benefits and potential harms of combining the two tests are uncertain. In general, FOBT should precede sigmoidoscopy because a positive result is an indication for colonoscopy, obviating the need for sigmoidoscopy.

Colonoscopy is the most sensitive and specific test for detecting cancer and large polyps but is associated with higher risks than other screening tests for colorectal cancer. These include a small risk for bleeding and risk for perforation, primarily associated with removal of polyps or with biopsies performed during screening. Colonoscopy also usually requires more highly trained personnel, overnight bowel preparation, sedation, and longer recovery time (which may necessitate transportation for the patient). It is not certain whether the potential added benefits of colonoscopy relative to screening alternatives are large enough to justify the added risks and inconvenience for all patients.

Initial costs of colonoscopy are higher than the costs of other tests. Estimates of cost-effectiveness, however, suggest that, from a societal perspective, compared with no screening, all methods of screening for colorectal cancer are likely to be as cost-effective as other clinical preventive services—less than $30 000 per additional year of life gained. The brief review of the evidence that is normally included in USPSTF recommendations is available in the complete Recommendation and Rationale statement on the USPSTF Web site (http://www.preventiveservices.ahrq.gov).

The American Cancer Society recommends screening people at average risk for colorectal cancer beginning at 50 years of age by 1) FOBT annually, 2) flexible sigmoidoscopy every 5 years, 3) annual FOBT plus flexible sigmoidoscopy every 5 years, 4) double-contrast barium enema every 5 years, or 5) colonoscopy every 10 years (2). The American Cancer Society does not recommend digital rectal examination as a stand-alone screening test for colorectal cancer. Similar recommendations are issued by the American College of Surgeons, the American College of Obstetricians and Gynecologists, and the American Academy of Family Physicians (35). The American Gastroenterological Association, as part of a consortium of related professional organizations, also issues similar recommendations, which are currently being updated (1). The American College of Physicians–American Society of Internal Medicine does not have current guidelines on screening. The Canadian Task Force on Preventive Health Care concludes that there is good evidence to recommend annual or biennial FOBT and fair evidence to recommend sigmoidoscopy as part of the periodic health examination in average-risk adults after 50 years of age; evidence is insufficient to recommend for or against colonoscopy or combined FOBT and sigmoidoscopy (6).

Appendix

Members of the U.S. Preventive Services Task Force are Alfred O. Berg, MD, MPH, Chair (University of Washington, Seattle, Washington); Janet D. Allan, PhD, RN, CS, Vice-Chair (University of Texas Health Science Center, San Antonio, Texas); Paul S. Frame, MD (Tri-County Family Medicine, Cohocton, and University of Rochester, Rochester, New York); Charles J. Homer, MD, MPH (National Initiative for Children's Healthcare Quality, Boston, Massachusetts); Mark S. Johnson, MD, MPH (University of Medicine and Dentistry of New Jersey–New Jersey Medical School, Newark, New Jersey); Jonathan D. Klein, MD, MPH (University of Rochester School of Medicine, Rochester, New York); Tracy A. Lieu, MD, MPH (Harvard Pilgrim Health Care and Harvard Medical School, Boston, Massachusetts); Cynthia D. Mulrow, MD, MSc (University of Texas Health Science Center, Audie L. Murphy Memorial Veterans Hospital, San Antonio, Texas); C. Tracy Orleans, PhD (The Robert Wood Johnson Foundation, Princeton, New Jersey); Jeffrey F. Peipert, MD, MPH (Women and Infants' Hospital, Providence, Rhode Island); Nola J. Pender, PhD, RN (University of Michigan, Ann Arbor, Michigan); Albert L. Siu, MD, MSPH (Mount Sinai School of Medicine and The Mount Sinai Medical Center, New York, New York); Steven M. Teutsch, MD, MPH (Merck & Company, Inc., West Point, Pennsylvania); Carolyn Westhoff, MD, MSc (Columbia University College of Physicians and Surgeons, New York, New York); and Steven H. Woolf, MD, MPH (Virginia Commonwealth University, Fairfax, Virginia).

Table Jump PlaceholderAppendix Table 1.  U.S. Preventive Services Task Force Grades and Recommendations
Table Jump PlaceholderAppendix Table 2.  U.S. Preventive Services Task Force Grades for Strength of Overall Evidence
Winawer SJ, Fletcher RH, Miller L, Godlee F, Stolar MH, Mulrow CD, et al..  Colorectal cancer screening: clinical guidelines and rationale. Gastroenterology. 1997; 112:594-642. PubMed
CrossRef
 
Byers T, Levin B, Rothenberger D, Dodd GD, Smith RA.  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; 47:154-60. PubMed
 
Goldstein MM, Messing EM.  Prostate and bladder cancer screening. J Am Coll Surg. 1998; 186:63-74. PubMed
 
.  Primary and preventive care: periodic assessments. American College of Obstetricians and Gynecologists. ACOG Committee Opinion 246. Washington, DC: American Coll of Obstetricians and Gynecologists; 2000.
 
Summary of policy recommendations for periodic health examination. Revision 5.0. August 2001. American Academy of Family Physicians. Accessed athttp://www.aafp.org/exam/on 17 May 2002.
 
.  Colorectal cancer screening. Recommendations statement from the Canadian Task Force on Preventive Health Care. CMAJ. 2001; 165:206-8. PubMed
 

Figures

Tables

Table Jump PlaceholderAppendix Table 1.  U.S. Preventive Services Task Force Grades and Recommendations
Table Jump PlaceholderAppendix Table 2.  U.S. Preventive Services Task Force Grades for Strength of Overall Evidence

References

Winawer SJ, Fletcher RH, Miller L, Godlee F, Stolar MH, Mulrow CD, et al..  Colorectal cancer screening: clinical guidelines and rationale. Gastroenterology. 1997; 112:594-642. PubMed
CrossRef
 
Byers T, Levin B, Rothenberger D, Dodd GD, Smith RA.  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; 47:154-60. PubMed
 
Goldstein MM, Messing EM.  Prostate and bladder cancer screening. J Am Coll Surg. 1998; 186:63-74. PubMed
 
.  Primary and preventive care: periodic assessments. American College of Obstetricians and Gynecologists. ACOG Committee Opinion 246. Washington, DC: American Coll of Obstetricians and Gynecologists; 2000.
 
Summary of policy recommendations for periodic health examination. Revision 5.0. August 2001. American Academy of Family Physicians. Accessed athttp://www.aafp.org/exam/on 17 May 2002.
 
.  Colorectal cancer screening. Recommendations statement from the Canadian Task Force on Preventive Health Care. CMAJ. 2001; 165:206-8. PubMed
 

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Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

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Summary for Patients

Screening for Colorectal Cancer: Recommendations from the United States Preventive Services Task Force

The summary below is from the full reports titled “Cost-Effectiveness Analyses of Colorectal Cancer Screening: A Systematic Review for the U.S. Preventive Services Task Force,” “Screening for Colorectal Cancer: Recommendation and Rationale,” and “Screening for Colorectal Cancer in Adults at Average Risk: A Summary of the Evidence for the U.S. Preventive Services Task Force.” They are in the 16 July 2002 issue of Annals of Internal Medicine (volume 137, pages 96-104, 129-131, and 132-141). The first report was written by M Pignone, S Saha, T Hoerger, and J Mandelblatt; the second report was written by the U.S. Preventive Services Task Force; and the third report was written by M Pignone, M Rich, SM Teutsch, AO Berg, and KN Lohr.

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