Begin screening asymptomatic adults for colorectal cancer at age 50 years

Key takeaways:

• The ACP updated its guidance on colorectal cancer screening.
• The guidance conflicts with recommendations from the USPSTF, which lowered the recommended age to begin screening from age 50 to 45 years.

The ACP recently issued guidance that recommends colorectal cancer screening in asymptomatic, average-risk adults starting at age 50 years, going against some other organizations that recommend screening at an earlier age.

Recent data indicate that colorectal cancer (CRC) incidence is rising among younger adults.

“Although there has been a small increase in CRC incidence among persons aged 45 to 49 years, it is lower than in those aged 50 to 64 years and 65 to 74 years (35.1 vs. 71.9 vs. 128.9 per 100 000, respectively),” Amir Qaseem, MD, PhD, MHA, chief science officer and senior vice president of clinical policy and the Center for Evidence Reviews at ACP, and colleagues wrote in Annals of Internal Medicine.

Clinical guidelines addressing CRC screening vary on the recommended screening tests and time intervals, ages to stop and start screening and strength of recommendations, the authors wrote. So, they updated ACP’s 2019 stance.

To develop the updated guidance statement, they searched PubMed and the Guidelines International Network library for critically appraised clinical guidelines published after the ACP’s 2019 guidance. The researchers selected two guidelines for adaptation and adoption and used their modeling studies and evidence reviews to synthesize the evidence on benefits vs. risks, diagnostic test accuracy and effectiveness of CRC screening interventions.

CRC screening recommendations

“The thing for [primary care physicians] to keep in mind is when to start screening, when to stop and what tests to use,” Qaseem told Healio.

Qaseem and colleagues decided that in asymptomatic, average-risk adults:

• physicians should begin screening for CRC when patients are aged 50 years;
• physicians should stop screening patients aged older than 75 years;
• physicians should stop screening patients with a life expectancy of 10 years or less;
• physicians should consider not screening adults aged 45 to 49 years and discuss the uncertainty around harms and benefits of screening in this population;
• physicians should consult with their patient when selecting a screening test and consider harms and benefits, availability, frequency, cost and patient preferences;
• physicians should not screen for CRC with stool DNA, urine, capsule endoscopy, computed tomography colonography or serum screening tests; and
• as a screening test, physicians should use either colonoscopy every 10 years, flexible sigmoidoscopy every 10 years plus a fecal immunochemical test every 2 years or a fecal immunochemical or high-sensitivity guaiac fecal occult blood test every 2 years.

“The way I look at it, even now, all organizations agree we should be screening from 50 to 75. There is a net benefit; it helps in this age group. It reduces the incidence of cancer and mortality,” Qaseem said. “Let’s get everyone screened for CRC in this age group.”

For patients aged 45 to 49 years, though, “what we say is to consider not screening,” he said.

“There is no direct evidence. Incidence in this group is lower. The net benefit is much less favorable in this age group. We believe that the benefits do not outweigh the harms,” Qaseem said. “Sit down with your patients. Talk to them about uncertainty around benefits and discuss harms. Include them in the decision-making.”

Qaseem emphasized that the guidelines are only for patients of average risk, not high risk, and that physicians “should assess baseline risks of CRC, such as family history,” when making screening decisions for their patients.

Conflicting guidelines

The ACP’s updated guidance conflicts with those from other organizations such as the U.S. Preventive Services Task Force (USPSTF), which lowered the recommended age to start CRC screening from 50 to 45 years in 2021. Since then, research showed that screening rates more than doubled among adults aged 45 to 49 years.

In a related editorial, Michael Bretthauer, MD, PhD, a professor at the University of Oslo, and Yu-Xiao Yang, MD, an associate professor at the University of Pennsylvania Perelman School of Medicine, wrote that, “although the new ACP statement is at odds with USPSTF and American Cancer Society guidance in important ways and will spark debate in the United States, it is more in line with international guidelines.”

“The updated guidance statement from ACP advocates for reserving screening recommendations for tests and patient populations associated with favorable high-quality benefit–harm assessments,” they wrote. “It shifts away from the more-testing-to-more-people approach in other U.S. guidelines.”

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