The US Preventive Services Task Force (USPSTF) has recommended that individuals of average risk for colorectal cancer (CRC) should begin screening exams at 45 years of age instead of the traditional 50. The guideline changes updates its 2016 recommendations and aligns them with those of the American Cancer Society, which lowered the age for initiation of screening to 45 years in 2018. The guidelines were published in the paper, ‘Screening for Colorectal Cancer - US Preventive Services Task Force Recommendation Statement’, in JAMA.
"A concerning increase in colorectal cancer incidence among younger individuals (ie, younger than 50 years; defined as young-onset colorectal cancer) has been documented since the mid-1990s, with 11% of colon cancers and 15% of rectal cancers in 2020 occurring among patients younger than 50 years, compared with 5% and 9%, respectively, in 2010," said Dr Kimmie Ng, first author of an editorial in JAMA accompanying the article about the guideline change of the USPSTF and director of the Young-Onset Colorectal Cancer Center at Dana-Farber Cancer Institute.
Lowering the recommended age to initiate screening "will make colorectal cancer screening, which is so important, available to millions more people in the United States, and hopefully many more lives will be saved by catching colorectal cancer earlier, as well as by preventing colorectal cancer," added Ng.
The task force selected age 45 based on research showing that initiating screening at that age averted more early deaths than starting at age 50, with a relatively small increase in the number of colonoscopy complications. There is no change to the USPSTF 2016 recommendation to only selectively screen individuals aged 76 to 85, as research shows only small increases in life-years gained.
The accompanying JAMA editorial asked rhetorically whether the age of screening should be lowered even younger than age 45. While the majority of young-onset CRC diagnoses and deaths occurs in persons 45 to 49, the rate of increase in young-onset CRC is actually steepest in the very youngest patients. Colon cancer incidence is increasing by 2% per year in 20 to 29-year-olds, compared with 1.3% in 40 to 49-year-olds. Rectal cancer incidence is increasing by 3.2% per year in 20 to 29-year-olds and 30 to 39-year-olds, versus 2.3% in 40 to 49-year-olds.
"We are now seeing patients even younger than 45 - in their 20s and 30s - who are being diagnosed with this cancer and often at very late stages," said Ng. "Clearly the USPSTF recommendation to start screening at age 45 will not be enough to catch those young people who are being diagnosed."
Ultimately, optimal prevention and early detection of CRC in people younger than 45 will require further research into the underlying causes and risk factors of young-onset CRC, which have thus far remained elusive, said the editorial authors.
The authors also called for "bold steps" to translate the lowered age of beginning screening into meaningful decreases in CRC incidence and mortality, noting that despite the preventive benefits of colorectal cancer screening, only 68.8 percent of eligible individuals in the US undergo screening. The rate is lower among the uninsured and underinsured, those with low incomes, and racial and ethnic minorities. Barriers include lack of knowledge of the importance of screening, concerns about the invasive nature of colonoscopy, and lack of access to and provider recommendations for screening.
The editorial lists examples including public awareness campaigns, including those aimed at gaps in CRC incidence and mortality between Black and white Americans, and specific actions. Employers could provide 45-year-old employees with a paid "wellness day" to undergo CRC screening, or offer day care or transportation vouchers to overcome the logistical hurdles of colonoscopies. Health systems could offer weekend or after-hours appointments for colonoscopies.
The new recommendation "represents an important policy change," the authors wrote, "to drive progress toward reducing colorectal cancer incidence and mortality."
Although the benefits of screening for colorectal cancer are well established, the following important evidence gaps that need to be addressed by additional research persist:
- Randomised trials that directly compare the effectiveness of different colorectal cancer screening strategies (including hybrid strategies that switch between modalities over time) to reduce colorectal cancer mortality are needed.
- Studies are needed on screening effectiveness in adults younger than 50 years and whether screening strategies should be tailored in these populations.
- More research is needed to understand the factors that contribute to increased colorectal cancer incidence and mortality in Black adults, such as access to and availability of care and characteristics of systems providing health care. Once these factors are identified, more research is needed to test interventions designed to mitigate these differences for Black adults.
- More studies evaluating the direct effectiveness of screening with sDNA-FIT on colorectal cancer mortality outcomes and studies that report outcomes of patients who receive abnormal sDNA-FIT results but subsequently negative colonoscopy results are needed.
- More studies evaluating the direct effectiveness of screening with CT colonography on colorectal cancer mortality are needed, as well as more studies that report on long-term consequences of identifying extracolonic findings on colorectal cancer screening.
- More research is needed to understand the uptake of and adherence to individual screening tests (such as adherence to repeated screening colonoscopy after ten years and repeated stool tests annually) and the effect adherence has on the overall benefits of a screening program. Similarly, more research is needed on the accuracy and effectiveness of emerging screening technologies such as serum- and urine-based colorectal cancer screening tests and capsule endoscopy tests to potentially improve acceptance and adherence to colorectal cancer screening, if found to be accurate and effective.
The USPSTF is an independent panel of experts funded by the US Department of Health and Human Services. It systematically reviews the evidence of effectiveness of preventive services and develops recommendations. American health insurance groups are required to cover, at no charge to the patient, any service that the USPSTF recommends with a grade A or B level of evidence, regardless of how much it costs. The task force recommendation means that insurers will be required to cover preventive procedures such as colonoscopies and stool tests designed to detect colon cancer in early stages.
To access the guidelines, please click here