Colorectal Cancer

Colon cancer remains a common condition in the United States, with 1 in 24 individuals developing colorectal cancer (CRC) during their lifetime.2,12 Across genders, colon cancer represents the second most common cause of cancer death.23 Increasing age, male sex, Black race, inflammatory bowel disease, and certain cancer risk syndromes (eg, familial adenomatous polyposis) are associated with increased risk of CRC diagnosis.23,24 In addition to an increased risk of CRC diagnosis, Black adults also have disproportionately high mortality from CRC, with this disparity increasing over the past several decades.23,24

The USPSTF and ACS strongly recommend screening average-risk individuals from age 50 to 75 years and discourage screening in patients older than 85 years (Table 5).24,25 As of May 2021, the USPSTF aligns with the ACS guidelines to include a qualified recommendation to begin screening average-risk individuals at age 45.24 There are multiple screening tests available, categorized as either stool-based or direct visualization tests (Table 6).25 The ACS recommends screening with either a stool-based test or a direct visualization test.25 Stool-based tests, such as the guaiac-based fecal occult blood test (gFOBT) and fecal immunochemical test (FIT), can be performed yearly.25 Multi-targeted stool DNA plus FIT (FIT-DNA) can be performed every 3 years.25 A positive stool-based test should be followed up by a diagnostic colonoscopy.24,25 The benefits of stool-based tests are that they are low cost, noninvasive, home-based, and do not require bowel prep or anesthesia. The harms associated with this type of testing are largely due to adverse events during follow-up colonoscopy.25  

Direct visualization tests have longer recommended screening intervals: every 10 years for colonoscopy and every 5 years for CT colonography and flexible sigmoidoscopy.25 These tests have high sensitivity and specificity.25 Colonoscopy is also associated with strong, high-quality evidence of reducing mortality from colon cancer, and only colonoscopy and sigmoidoscopy allow the opportunity for removal of precancerous polyps.24,25 Risks associated with direct visualization tests are related to bowel preparation prior to the procedure, overdiagnosis and overtreatment, and adverse events during the procedure (eg, colonic perforation and risks associated with anesthesia).24,25

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Current guidelines do not recommend 1 test over another. Patient preference and resource availability should be taken into consideration when selecting an appropriate screening modality.24 Clinicians should identify high-risk individuals who may benefit from early screening.23,24,26

Table 5. Colorectal Cancer Screening Guidelines

USPSTF24 (2021)ACS25 (2018)
• Screen adults aged 50-75 y
• Offer screening starting at age 45 y
In adults aged 76-86 y, engage in shared decision-making
• Frequency varies by modality (see Table 6)
• Avoid screening after age 85 y
• Screen adults aged 45-75 y
• In adults aged 76-86 y engage, in shared decision-making
• Frequency varies by modality (see Table 6)
• Avoid screening age after age 85 y
ACS, American Cancer Society; USPSTF, United States Preventative Services Task Force

Table 6. Colorectal Cancer Screening Modalities25

Direct visualizationRecommended Screening IntervalType of Screening
Colonoscopy10 yearsDirect visualization
Flexible sigmoidoscopy5 yearsDirect visualization
CT colonography5 yearsDirect visualization
FIT1 yearStool based
gFOBT1 yearStool based
FIT-DNA3 yearsStool based
FIT, fecal immunochemical test; gFOBT, guaiac fecal occult blood test; FIT-DNA, fecal immunochemical test-DNA

This article originally appeared on Clinical Advisor