ACG Guidelines for Colorectal Cancer Screening
Am Fam Physician. 2009 Sep 15;80(6):647-651.
Guideline source: American College of Gastroenterology
Literature search described? Yes
Evidence rating system used? Yes
Published source: American Journal of Gastroenterology, March 2009
Available at: http://www.nature.com/ajg/journal/v104/n3/full/ajg2009104a.html (subscription required)
In 2000, the American College of Gastroenterology (ACG) became the first organization to recommend colonoscopy as the preferred screening method for colorectal cancer. The ACG updated its screening recommendations in 2008, and continues to support colonoscopy in average-risk patients every 10 years based on the evidence of effectiveness, cost-effectiveness, and patient acceptance. Recommendations from the 2008 guidelines that differ from the previous guidelines are presented in Table 1.
Table 1 Updates to the 2000 American College of Gastroenterology Recommendations on Screening for Colorectal Cancer
Updates to the 2000 American College of Gastroenterology Recommendations on Screening for Colorectal Cancer
Screening tests are divided into cancer prevention and cancer detection tests. Cancer prevention tests are preferred over detection tests.
Screening is recommended in blacks beginning at 45 years of age.
Computed tomography colonography every five years replaces double contrast barium enema as the radiographic screening alternative when patients decline colonoscopy.
Fecal immunochemical test replaces guaiac-based fecal occult blood testing. Fecal immunochemical test is the preferred cancer detection test.
Annual Hemoccult Sensa and fecal DNA testing every three years are alternative cancer detection tests.
A family history of small tubular adenomas in first-degree relatives is not considered to increase the risk of colorectal cancer.
Persons with only one first-degree relative with colorectal cancer or advanced adenomas diagnosed at 60 years or older may be screened as average-risk persons.
Adapted with permission from Rex DK, Johnson DA, Anderson JC, Schoenfeld PS, Burke CA, Inadomi JM, for the American College of Gastroenterology. American College of Gastroenterology guidelines for colorectal cancer screening 2008. Am J Gastroenterol. 2009;104(3):740.
Cancer Prevention Tests vs. Cancer Detection Tests
In 2008, a joint committee of the U.S. Multi-society Task Force, the American Cancer Society, and the American College of Radiology released a guideline that divided colorectal cancer screening tests into two groups: cancer prevention tests and cancer detection tests. Prevention tests are capable of imaging cancer and polyps, whereas detection tests have low sensitivity for polyps and lower sensitivity for cancer compared with prevention tests. The ACG supports this division of tests and specifies that the preferred prevention test should be colonoscopy every 10 years, and the preferred detection test should be annual fecal immunochemical test (FIT) for occult bleeding (Table 2).
Table 2 Colorectal Cancer Screening Recommendations
Colorectal Cancer Screening Recommendations
Preferred CRC screening recommendations
Cancer prevention tests should be offered first; the preferred CRC prevention test is colonoscopy every 10 years, beginning at 50 years of age (Grade 1 B)
Screening should begin at 45 years of age in blacks (Grade 2 C)
Cancer detection tests should be offered to patients who decline colonoscopy or another cancer prevention test; the preferredcancer detection test is annual FIT for blood (Grade 1 B)
Alternative CRC prevention tests
Flexible sigmoidoscopy every five to 10 years (Grade 2 B)
Computed tomography colonography every five years (Grade 1 C)
Alternative cancer detection tests
Annual Hemoccult Sensa (Grade 1 B)
Fecal DNA testing every three years (Grade 2 B)
Recommendations for screening when family history is positive but evaluation for HNPCC considered not indicated
Patients with one first-degree relative with CRC or advanced adenoma diagnosed at 60 years or older should be screened the same as patients at average risk (Grade 2 B)
Patients with one first-degree relative with CRC or advanced adenoma diagnosed before 60 years of age, or two first-degree relatives with CRC or advanced adenomas diagnosed at any age, should undergo colonoscopy every five years beginning at 40 years of age or 10 years younger than the age of the youngest affected relative at the time of diagnosis (Grade 2 B)
Patients with classic FAP (more than 100 adenomas) should be advised to pursue genetic counseling and genetic testing if they have siblings or children who could potentially benefit from this testing (Grade 2 B)
Patients with known FAP and those at risk of FAP based on family history (and in whom genetic testing has not been performed) should undergo annual flexible sigmoidoscopy or colonoscopy, as appropriate, until colectomy is deemed by physician and patient as the best treatment (Grade 2 B)
Patients with retained rectum after subtotal colectomy should undergo flexible sigmoidoscopy every six to 12 months (Grade 2 B)
Patients with classic FAP, in whom genetic testing is negative, should undergo genetic testing for biallelic MYH mutations; patients with 10 to 100 adenomas can be considered for genetic testing for attenuated FAP and, if negative, MYH-associated polyposis (Grade 2 C)
Patients who meet the Bethesda criteria for HNPCC should undergo microsatellite instability testing of their tumor or a family member's tumor and/or tumor immunohistochemical staining for mismatch repair proteins (Grade 2 B)
Patients with positive tests can be offered genetic testing; those with positive genetic testing, or those at risk when genetic testing is unsuccessful in an affected proband, should undergo colonoscopy every two years beginning at 20 to 25 years of age until 40 years of age, and annually thereafter (Grade 2 B)
CRC = colorectal cancer; FAP = familial adenomatous polyposis; FIT = fecal immunochemical test; HNPCC = hereditary nonpolyposis colorectal cancer.
Grade 1 A = strong recommendation, high-quality evidence; Grade 1 B = strong recommendation, moderate-quality evidence; Grade 1 C = strong recommendation, low- or very low-quality evidence; Grade 2 A = weak recommendation, high-quality evidence; Grade 2 B = weak recommendation, moderate-quality evidence; Grade 2 C = weak recommendation, low- or very low-quality evidence.
Adapted with permission from Rex DK, Johnson DA, Anderson JC, Schoenfeld PS, Burke CA, Inadomi JM, for the American College of Gastroenterology. American College of Gastroenterology guidelines for colorectal cancer screening 2008. Am J Gastroenterol. 2009;104(3):741.
Patients should be offered colonoscopy beginning at 50 years of age. If patients have economic issues that preclude primary screening with colonoscopy, or if patients decline colonoscopy, the physician should offer an alternative prevention test or the preferred detection test (i.e., occult blood detection through FIT).
The ACG supports annual FIT as a preferred cancer detection test in place of guaiac-based fecal occult blood testing. Although the guaiac-based Hemoccult Sensa and the fecal DNA test are possible alternative detection tests, FIT is less expensive than fecal DNA testing and has produced more extensive data than the Hemoccult Sensa.
Age to Begin Screening in Persons at Average Risk
The ACG recommends that colorectal cancer screening begin at 50 years of age in men and women at average risk (i.e., those without a family history of colorectal neoplasia). However, screening should begin at 45 years of age in black men and women. Evidence supports screening for colorectal cancer before 50 years of age in persons with an extreme smoking history or obesity, although a formal recommendation has not been issued.
Family History Screening
The ACG no longer recommends an increased level of screening for a simple family history of adenomas in a first-degree relative. Patients with one first-degree relative with colorectal cancer or advanced adenoma (i.e., adenoma greater than 1 cm, or with high-grade dysplasia or villous elements) diagnosed at 60 years or older should receive the same screening as average-risk patients. Patients with one first-degree relative diagnosed before 60 years of age, or with two first-degree relatives diagnosed at any age, should have a screening colonoscopy every five years beginning at 40 years of age or 10 years younger than the age of the youngest affected relative at the time of diagnosis. Table 2 summarizes the ACG recommendations for modification of the screening approach when a family history of colorectal polyps and cancer are not suggestive of hereditary nonpolyposis colorectal cancer (HNPCC).
Familial Adenomatous Polyposis
Patients with features of an inherited colorectal cancer syndrome should be encouraged to seek genetic counseling and, if appropriate, genetic testing (Table 2). Patients with familial adenomatous polyposis (FAP) should undergo APC mutation testing. If this test is negative, MYH mutation testing is recommended. Patients with FAP and those at risk of FAP should be screened annually with flexible sigmoidoscopy or colonoscopy until the patient and physician determine that a colectomy is the best treatment. Endoscopic assessment every six to 12 months after surgery is recommended for patients with a retained rectum after subtotal colectomy. Genetic counseling, APC and MYH mutation testing, and individualized colonoscopy surveillance should be considered in patients who have fewer than 100 colorectal polyps. Upper endoscopic surveillance is recommended for patients with FAP or MYH-associated polyposis.
Hereditary Nonpolyposis Colorectal Cancer
Patients who meet the Bethesda criteria for HNPCC should undergo microsatellite instability testing of their tumor or an affected family member's tumor (Table 2). This may be combined with tumor immunohistochemical staining for mismatch repair proteins. Patients with positive tests may be offered genetic counseling and should undergo colonoscopy every two years beginning at 20 to 25 years of age until 40 years of age, and annually thereafter.
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