Recommendations made by the USPSTF are independent of the U.S. government. They should not be construed as an official position of the Agency for Healthcare Research and Quality or the U.S. Department of Health and Human Services.
Patient Population Under Consideration
This recommendation applies to asymptomatic adults 45 years or older who are at average risk of colorectal cancer (ie, no prior diagnosis of colorectal cancer, adenomatous polyps, or inflammatory bowel disease; no personal diagnosis or family history of known genetic disorders that predispose them to a high lifetime risk of colorectal cancer [such as Lynch syndrome or familial adenomatous polyposis]).
Assessment of Risk
Age is one of the most important risk factors for colorectal cancer, with incidence rates increasing with age and nearly 94% of new cases of colorectal cancer occurring in adults 45 years or older.2 Rates of colorectal cancer incidence are higher in Black adults and American Indian and Alaskan Native adults,2 persons with a family history of colorectal cancer (even in the absence of any known inherited syndrome such as Lynch syndrome or familial adenomatous polyposis),8 men,2 and persons with other risk factors (such as obesity, diabetes, long-term smoking, and unhealthy alcohol use).9 However, all adults 45 years or older should be offered screening, even if these risk factors are absent.
The risks and benefits of different screening tests vary. See Table 1 for characteristics of recommended screening strategies, which may include combinations of screening tests. Because of limited available evidence,9,10 the USPSTF recommendation does not include serum tests, urine tests, or capsule endoscopy for colorectal cancer screening. Recommended stool-based and direct visualization screening tests are described below.
Stool-based tests include the high-sensitivity guaiac fecal occult blood test (gFOBT), fecal immunochemical test (FIT), and stool DNA test. Both high-sensitivity gFOBT and FIT detect blood in the stool; however, they use different methods. High-sensitivity gFOBT is based on chemical detection of blood, while FIT uses antibodies to detect blood.11 Stool DNA tests detect DNA biomarkers for cancer in cells shed from the lining of the colon and rectum into stool.11 Currently, the only stool DNA test approved by the US Food and Drug Administration is a multitarget stool DNA test that also includes a FIT component, referred to as sDNA-FIT in this recommendation. When stool-based tests reveal abnormal results, follow-up with colonoscopy is needed for further evaluation. Among the stool-based tests, screening with annual FIT or annual sDNA-FIT provides an estimated greater life-years gained than annual high-sensitivity gFOBT or sDNA-FIT every 3 years.12,13 Additionally, modeling estimates that screening with sDNA-FIT annually would result in more colonoscopies than annual screening with FIT.12,13 However, sDNA-FIT every 1 to 3 years is estimated to provide a reasonable balance of life years gained per estimated follow-up colonoscopy compared with no screening. Currently, there is uncertainty around the accuracy of high-sensitivity gFOBT to detect colorectal cancer and advanced adenomas, although it is likely lower than the accuracy of FIT and sDNA-FIT, and high-sensitivity gFOBT is more difficult for patients to administer.9,10 However, randomized trials demonstrate direct evidence of decreased deaths from colorectal cancer when screening with non–high-sensitivity gFOBT is performed.9,10
Direct Visualization Tests
Direct visualization tests to screen for colorectal cancer include colonoscopy, CT colonography, and flexible sigmoidoscopy. All 3 screening tests visualize the inside of the colon and rectum, although flexible sigmoidoscopy can only visualize the rectum, sigmoid colon, and descending colon, while colonoscopy and CT colonography can generally visualize the entire colon. For colonoscopy and flexible sigmoidoscopy, a camera is used to visualize the inside of the colon, while CT colonography uses x-ray images. When abnormal results are found on flexible sigmoidoscopy or CT colonography, follow-up with colonoscopy is needed for further evaluation. Among the direct visualization tests, a colonoscopy every 10 years or CT colonography every 5 years have greater estimated life-years gained than flexible sigmoidoscopy every 5 years.12,13 Unlike colonoscopy and flexible sigmoidoscopy, CT colonography may reveal extracolonic findings that require additional workup, which could lead to other potential benefits or harms.9,10
Starting and Stopping Ages
The USPSTF recommends offering colorectal cancer screening starting at age 45 years. Although the absolute risk of developing colorectal cancer is much lower in adults younger than 50 years (20.0 new colorectal cancer cases per 100,000 persons aged 40 to 49 years, 47.8 new cases per 100,000 persons aged 50 to 59 years, and 105.2 new cases per 100,000 persons 60 years or older14), age-period-cohort analysis indicates a recent trend for increasing risk of colorectal cancer in birth cohorts of adults younger than 50 years.15 The benefit of reducing colorectal cancer deaths by screening for colorectal cancer in adults 50 years or older is well established through trial data. Some of these trials16-18 also included adults younger than 50 years, although results are not reported separately for younger age groups. Additionally, modeling performed by the Cancer Intervention and Surveillance Modeling Network (CISNET) suggests that starting colorectal cancer screening at age 45 years may moderately increase life-years gained and decrease colorectal cancer cases and deaths compared with beginning screening at age 50 years.12,13
In adults aged 76 to 85 years, the age at which the balance of benefits and harms of colorectal cancer screening becomes less favorable and screening should be stopped varies based on a patient’s health status (eg, life expectancy, comorbid conditions), prior screening status, and individual preferences.19 Limited evidence suggests that harms from colonoscopy, such as perforation and bleeding, and extracolonic findings on CT colonography increase with age.9,10 Modeling studies estimate that generally, few additional life-years are gained when screening is extended past age 75 years among average-risk adults who have previously received adequate screening.12,13
In adults 86 years or older, evidence on benefits and harms of colorectal cancer screening is lacking, and competing causes of mortality likely preclude any survival benefit that would outweigh the harms of screening.
Recommended intervals for colorectal cancer screening tests include
- High-sensitivity gFOBT or FIT every year
- sDNA-FIT every 1 to 3 years
- CT colonography every 5 years
- Flexible sigmoidoscopy every 5 years
- Flexible sigmoidoscopy every 10 years + FIT every year
- Colonoscopy screening every 10 years
Treatment or Interventions
Localized cancer is generally treated with surgical resection.20 Depending on cancer location and stage/progression, additional treatment options may include adjuvant chemotherapy, neoadjuvant chemotherapy, chemoradiation, and targeted therapies.20,21
Screening for Colorectal Cancer in Black Adults
Colorectal Cancer Burden
Black adults have the highest incidence of and mortality from colorectal cancer compared with other races/ethnicities. From 2013 to 2017, incidence rates for colorectal cancer were 43.6 cases per 100,000 Black adults, 39.0 cases per 100,000 American Indian/Alaska Native adults, 37.8 cases per 100,000 White adults, 33.7 cases per 100,000 Hispanic/Latino adults, and 31.8 cases per 100,000 Asian/Pacific Islander adults.22 Colorectal cancer death rates in 2014 to 2018 were 18.0 deaths per 100,000 Black adults, 15.1 deaths per 100,000 American Indian/Alaska Native adults, 13.6 deaths per 100,000 non-Hispanic White adults, 10.9 deaths per 100,000 Hispanic/Latino adults, and 9.4 deaths per 100,000 Asian/Pacific Islander adults.23
The causes for these health disparities are complex; recent evidence points to inequities in the access to and utilization and quality of colorectal cancer screening and treatment as the primary driver for this health disparity rather than genetic differences.24,25 The recent trend for increasing colorectal cancer incidence in adults younger than 50 years has been observed in White and Hispanic/Latino adults but not Black or Asian/Pacific Islander adults.26 However, despite these trends, Black adults across all age groups, including those younger than 50 years, continue to have a higher incidence of and mortality from colorectal cancer than White adults.
The USPSTF sought evidence on the potential benefits and harms of colorectal cancer screening in Black adults; however, little empirical evidence was identified. Although some studies on the effectiveness of colorectal cancer screening included non-White participants, no studies reported results of screening by race/ethnicity.9,10 Few studies on screening accuracy reported findings by race; however, those studies that did generally found no difference in accuracy to detect colorectal cancer in Black adults compared with White adults for FIT (in 1 study27) or sDNA-FIT (in 1 study28). The 4 studies of screening colonoscopy that reported harms by race/ethnicity had inconsistent findings. No other studies on harms reported results by race/ethnicity. Modeling studies that assume perfect adherence to screening and no racial differences in screening accuracy or natural history of colorectal cancer (ie, no biological differences in the risks of adenoma onset and progression to colorectal cancer),25 but lower relative colorectal cancer survival rates29 and increased all-cause mortality in Black adults vs White adults,30 estimate similar life-years gained from screening Black adults and White adults and a similar balance of the benefits and harms for each screening strategy.12,13
Advising Black Adults
Based on the limited available empirical evidence, the USPSTF is not able to make a separate, specific recommendation on colorectal cancer screening in Black adults. Results from CISNET modeling also do not support different screening strategies by race.12,13 Other organizations such as the US Multi-Society Task Force recommend starting screening in Black adults at age 45 years while starting screening at age 50 years for persons of other races.31 The current USPSTF statement recommends starting screening for everyone at age 45 years, including Black adults.
The USPSTF recognizes the higher colorectal cancer incidence and mortality in Black adults and strongly encourages clinicians to ensure their Black patients receive recommended colorectal cancer screening, follow-up, and treatment. The USPSTF encourages the development of systems of care to ensure adults receive high-quality care across the continuum of screening and treatment, with special attention to Black communities, which historically experience worse colorectal cancer health outcomes.
Maintaining comparable benefits and harms of screening with the various strategies requires that patients, clinicians, and health care organizations adhere to currently recommended protocols for screening intervals, follow-up colonoscopy, and treatment. Each screening test has different considerations for implementation that may facilitate patient uptake of and adherence to screening or serve as a barrier to screening (see Table 1 for additional details). Implementation considerations include where the screening test is performed, who performs the screening procedure, the need for preprocedure bowel preparation, the need for anesthesia or sedation during the test, and follow-up procedures for abnormal findings on a screening test. These considerations have implications for how feasible and preferable a given screening test is for an individual. Discussion of implementation considerations with patients may help better identify screening tests that are more likely to be completed by a given individual.
Stool-based screening requires persons to collect samples directly from their feces, which may be unpleasant for some, but the test is quick and noninvasive and can be done at home (the sample is mailed to the laboratory for testing), and no bowel preparation is needed to perform the screening test. The benefits of stool-based testing accrue over frequent, repeated testing, thus requiring commitment and adherence to screening intervals to achieve a substantial benefit in decreased colorectal cancer mortality.
Positive results on stool-based screening tests require follow-up with colonoscopy for the screening benefits to be achieved. Screening with high-sensitivity gFOBT requires some dietary and medication restrictions prior to collecting stool samples,32 while FIT and sDNA-FIT33,34 do not. Test specimens can be collected from a single stool sample with FIT and sDNA-FIT33,34 (sDNA-FIT involves collecting an entire bowel movement), while collection of samples from 3 separate bowel movements is required for high-sensitivity gFOBT screening.32
Direct Visualization Tests
Screening by direct visualization tests must be performed in a clinical setting rather than in the home. When performed alone, direct visualization tests allow for a much longer time between screenings compared with stool-based screening. Colonoscopy has the longest length between screenings (10 years when screening results are negative), whereas flexible sigmoidoscopy and CT colonography allow 5 years between screenings if performed alone. Direct visualization tests all require bowel preparation prior to the screening test, although specific regimens may depend on the specific screening test being performed.35 The use of sedation or anesthesia during the procedure also varies by screening test. Sedation or anesthesia is usually used during colonoscopy; hence, assistance with transportation home and recovery time after colonoscopy is required.36 Abnormal findings identified by flexible sigmoidoscopy or CT colonography screening require follow-up colonoscopy for screening benefits to be achieved.
Additional Tools and Resources
The National Cancer Institute and the Centers for Disease Control and Prevention have developed patient and clinician guides on screening for colorectal cancer:
The Community Preventive Services Task Force has also issued recommendations on interventions to increase colorectal cancer screening at https://www.thecommunityguide.org/content/task-force-findings-cancer-prevention-and-control.
Other Related USPSTF Recommendations
The USPSTF has a recommendation statement on aspirin use for the primary prevention of cardiovascular disease and colorectal cancer in average-risk adults (available at https://uspreventiveservicestaskforce.org).37
Table 1. Characteristics Of Colorectal Screening Strategies