The U.S. Multi-Society Task Force on Colorectal Cancer (CRC) has lowered the recommended age to start CRC screening from 50 to 45 years of age for all average-risk individuals.
Although no studies have directly demonstrated the result of lowering the age of screening, lead author Swati G. Patel, MD, of University of Colorado Anschutz Medical Center, Aurora, and colleagues suggested that the increasing incidence of advanced CRC among younger individuals, coupled with the net benefit of screening, warrant a lower age threshold.
“Recent data ... show that CRC incidence rates in individuals ages 50 to 64 have increased by 1% annually between 2011 and 2016,” the authors wrote in Gastroenterology. “Similarly, CRC incidence and mortality rates in persons under age 50, termed early-age onset CRC (EAO-CRC), are also increasing.”
The task force of nine experts, representing the American Gastroenterological Association, the American College of Gastroenterology, and the American Society for Gastrointestinal Endoscopy, conducted a literature review and generated recommendations using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria. In addition to recommending a lower age for initial screening, Dr. Patel and colleagues provided guidance for cessation of screening among older individuals.
Guidance for screening initiation
According to the authors, the present risk of CRC among younger individuals mirrors the historical risk for older individuals before screening was prevalent.
“The current CRC incidence rates in individuals ages 45 to 49 are similar to the incidence rates observed in 50-year-olds in 1992, before widespread CRC screening was performed,” they wrote.
Elevated rates among younger people have been disproportionately driven by rectal cancer, according to the authors. From 2006 to 2015, incidence of rectal cancer among Americans under 50 increased 1.7% per year, compared with 0.7% per year for colon cancer, based on data from the North American Association of Central Cancer Registries.
Associated mortality rates also increased, the authors noted. From 1999-2019, mortality from colon cancer among people 45-49 years increased from 6.4 to 6.6 deaths per 100,000 individuals, while deaths from rectal cancer increased from 1.3 to 1.7 per 100,000, according to the CDC. Concurrently, CRC-associated mortality rates among older individuals generally declined.
While these findings suggest a growing disease burden among the under-50-year age group, controlled data demonstrating the effects of earlier screening are lacking, Dr. Patel and colleagues noted. Still, they predicted that expanded screening would generate a net benefit.
“Although there are no CRC screening safety data for average-risk individuals [younger than] 50, there are ample data that colonoscopy for other indications (screening based on family history, symptom evaluation, etc.) is safer when comparing younger versus older individuals,” they wrote.
Supporting this claim, the authors cited three independently generated microsimulation models from the Agency for Healthcare Research and Quality that “showed a favorable balance of life-years gained compared with adverse events,” given 100% compliance.
Guidance for screening cessation
Like the situation with younger individuals, minimal data are available to determine the best time for screening cessation, according to the task force.
“There are no randomized or observational studies after 2017 that enrolled individuals over age 75 to inform the appropriate time to stop CRC screening,” the authors wrote. “In our search of 37 relevant articles, only one presented primary data for when to stop screening.”
This one available study showed that some individuals older than 74 do in fact gain benefit from screening,
“For example,” Dr. Patel and colleagues wrote, “women without a history of screening and no comorbidities benefitted from annual fecal immunochemical test (FIT) screening until age 90, whereas unscreened men with or without comorbidities benefited from annual FIT screening until age 88. Conversely, screening was not beneficial beyond age 66 in men or women with severe comorbidities.”
The task force therefore recommended personalized screening for individuals 76-85 years of age “based on the balance of benefits and harms and individual patient clinical factors and preferences.”
Screening for individuals 86 years and older, according to the task force, is unnecessary.
The authors disclosed relationships with Olympus America, Bayer Pharmaceuticals, Janssen Pharmaceuticals, and others.
This article was updated on Jan. 3, 2022.