Key Points for Practice
• All adults at average risk of colorectal cancer should start routine screening at 45 years of age using high-sensitivity fecal testing or visual examination.
• The decision whether to perform screening in patients 76 to 85 years of age should be based on patient preference, life expectancy, health, and screening history.
• Screening should be discouraged in patients older than 85 years because the risks of mortality and screening complications are increased.
From the AFP Editors
Colorectal cancer (CRC) is the fourth most prevalent cancer in the United States and second leading cancer-related cause of death. More than one-half of CRCs are caused by lifestyle factors, including smoking, overweight or obesity, increased consumption of alcohol or red or processed meat, decreased intake of fiber and calcium, and less physical activity. Identifying and removing lesions at an earlier stage during CRC screening are associated with reduced incidence and mortality.
To support early identification and treatment, the American Cancer Society (ACS) has updated its 2008 guidance on counseling and referring patients at average risk of CRC based on new evidence regarding screening options and the ever-changing risk of CRC. To help physicians and patients in their decision making, the recommendations were categorized as strong (i.e., the benefits of the intervention, which most patients would select, outweigh the harms) or qualified (i.e., evidence of benefit or harm exists, but balance of benefits and harms is less clear, resulting in more varied patient decisions about screening).
45 YEARS OR OLDER
All adults at average risk of CRC should start routine screening at 45 years of age using high-sensitivity fecal testing or visual examination depending on patient preference and accessibility of the screening modality. Current options for screening include annual fecal immunochemical testing or high-sensitivity guaiac-based fecal occult blood testing; stool DNA testing every three years; computed tomographic colonography or flexible sigmoidoscopy every five years; or colonoscopy every 10 years. Patients who are screened via any method except colonoscopy whose results are positive should have follow-up colonoscopy performed.
The incidence of CRC has notably increased in younger adults, resulting in premature CRC-related mortality. Lowering the age of CRC screening to 45 years has been shown to improve the balance of benefits over harm for all patients at any risk level. Although the benefits that can be anticipated from screening in persons 45 to 49 years of age were considered less than those in patients for whom screening is typically recommended (i.e., those 50 years and older), the associated decreased prevalence of CRC and associated mortality were considered more beneficial than the potential harms of increased performance of colonoscopies. Routine screening starting at 45 years of age is a qualified recommendation, whereas screening those 50 years and older continues to be a strong recommendation, based on the available evidence.
75 TO 85 YEARS OF AGE
Healthy adults with an average risk of CRC who are anticipated to live longer than 10 years should be screened through 75 years of age (qualified recommendation), because studies have shown reduced mortality with screening in this age group. In addition, benefits of screening have been associated with a life expectancy of at least 10 years via a combination of early identification and prevention. The decision to perform screening in patients 76 to 85 years of age should be based on patient preference, life expectancy, health, and screening history (qualified recommendation), because the trade-off between benefits and harms (e.g., complications of colonoscopy) is debatable in this age group. Screening options not requiring colonoscopy may be preferred in this patient population.
OLDER THAN 85 YEARS
Screening should be discouraged in patients older than 85 years (qualified recommendation), because the risks of mortality and screening complications are increased, outweighing the benefits in this age group. Screening should be considered only in rare circumstances, such as for patients in excellent health who have not received screening.
Editor's Note: It's important to note that little evidence exists on outcomes of screening average-risk adults 45 through 49 years of age for colorectal cancer. The ACS recommendation to screen at these ages is based on increased CRC incidence at younger ages, microsimulation modeling, and observational studies that screening tests would perform similarly in this group. It is a “qualified” recommendation as opposed to “strong” because the balance of benefits and harms is less clear, leading to more individualized decisions about screening. The USPSTF also analyzed microsimulation models for its 2016 recommendation, but the findings of benefit before 50 years of age were not consistent across all models. The USPSTF (https://www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementFinal/colorectal-cancer-screening2) and AAFP (https://www.aafp.org/patient-care/clinical-recommendations/all/colorectal-cancer-adults.html) recommend that CRC screening start at 50 years of age. Also, the AAFP specifically recommends fecal immunochemical tests, flexible sigmoidoscopy, or colonoscopy for screening.—Sumi M. Sexton, MD, Editor-in-Chief of AFP
Guideline source: American Cancer Society
Evidence rating system used? Yes
Systematic literature search described? Yes
Guideline developed by participants without relevant financial ties to industry? No
Recommendations based on patient-oriented outcomes? Yes
Published source:CA Cancer J Clin. July 2018;68(4):250–281