June 3, 2021, 2:46 p.m. David Mitchell — Colorectal cancer is the third-leading cause of cancer-related deaths in the United States, and the American Cancer Society estimates that nearly 150,000 new cases will be diagnosed this year alone.
The U.S. Preventive Services Task Force recently finalized a recommendation statement (as well as an evidence review and modeling report) that aims to encourage more screening and reduce people’s risk of dying by lowering the age at which asymptomatic adults should begin being screened.
In a May 18 statement, task force Vice Chair Michael Barry, M.D., said, far too many Americans are not receiving “this lifesaving preventive service.”
“We hope that this new recommendation to screen people ages 45 to 49, coupled with our long-standing recommendation to screen people 50 to 75, will prevent more people from dying from colorectal cancer,” said Barry, who is the director of the Informed Medical Decisions Program in the Health Decision Sciences Center at Massachusetts General Hospital and a professor of medicine at Harvard Medical School.
The new recommendation replaces the task force’s 2016 recommendation statement, which gave an “A” recommendation designation to screening for CRC in adults ages 50 to 75 and called for individualized decision-making regarding screening adults ages 76 to 85.
The task force noted in its new recommendation that roughly one-fourth of eligible U.S. adults had never been screened as of 2016.
The AAFP split with the task force and issued its own recommendation in 2016, giving a “B” recommendation designation for CRC screening in adults ages 50 to 75. The difference in recommendation grade was based on the lack of evidence for benefits and harms for several of the screening strategies. The Academy’s recommendation, which highlighted key differences in screening modalities, aligned with the task force in regard to its “C” recommendation for screening adults ages 76 to 85.
The USPSTF’s new recommendation retains the “A” recommendation for screening adults ages 50-75 and “C” recommendation regarding adults ages 76 to 85. However, it added a recommendation to screen adults ages 45 to 49 with a “B” designation. (The American Cancer Society released a guideline in 2018 recommending that screening begin at age 45 for patients at average risk.)
The task force noted that CRC incidence has been declining for two decades in adults 55 and older. However, incidence of CRC in adults aged 40 to 49 years increased by almost 15% from 2000 to 2016, and more than 10% of new cases occur in people younger than 50.
In updating its recommendation, the task force commissioned a systematic evidence review to evaluate the benefits and harms of screening for CRC in adults 40 and older, with a focus on the effectiveness and comparative effectiveness of screening strategies and the accuracy of and serious harms associated with different screening tests. The review included more than 200 studies, more than one-third of which had been published since the previous evidence review.
In addition, the task force commissioned a comparative modeling report to provide information on how estimated life-years gained, cases averted and deaths from CRC averted vary based on different starting and stopping ages for various screening strategies.
Ultimately, the task force recommended two types of tests to screen for CRC:
The task force noted that these tests have different evidence levels to support their use, different performance levels in cancer detection and different risks of harms.
“Based on the evidence, there are many tests available that can effectively screen for colorectal cancer, and the right test is the one that gets done,” task force member Martha Kubik, Ph.D., R.N., a professor and director of the School of Nursing in the College of Health and Human Services at George Mason University, said in the USPSTF’s statement. “To encourage screening and help patients select the best test for them, we urge primary care clinicians to talk about the pros and cons of the various recommended options with their patients.”
The AAFP’s Commission on Health of the Public and Science is conducting a review of the updated USPSTF recommendation, which has both potential benefits and risks, said Chair Sarah Coles, M.D., of Phoenix.
“We will look closely at the available evidence, the benefits and harms of screening, as well as the potential impact on health equity,” said Coles, who is an associate professor at the University of Arizona College of Medicine – Phoenix Family Medicine Residency.
Finally, the task force called attention to several evidence gaps that require additional research. For example, Black adults have the highest incidence of and mortality from colorectal cancer, but the USPSTF noted in its recommendation statement that the factors that contribute to that inequity must be clearly identified before interventions can be designed to address it.
“The USPSTF recommendation will increase health care coverage for colorectal screening in a younger population but may not address larger systemic issues of lack of access to needed specialists or equipment, barriers to health care attainment and systemic racism,” said Coles, acknowledging that the Patient Protection and Affordable Care Act requires insurers to cover preventive services recommended by the task force. “The higher incidence and mortality from colorectal cancer among Black adults is a major area of concern. Health care disparities due to systemic racism are undoubtedly playing a significant role. Family physicians must be diligent in identifying signs and symptoms of colon cancer in their patients, have a structured and equitable approach to screening, collaborate with interprofessional teams to ensure access to high-quality screening programs, and continue to work on systemic improvements to reduce disparity.”