Updates to the screening guidelines for colorectal cancer (CRC) from the National Comprehensive Cancer Network (NCCN) include lowering the initial screening age for average-risk individuals and second- and third-degree family members with CRC, as well as an extension in the interval for surveillance colonoscopy for low-risk individuals. These updates were presented by Reid Ness, MD, MPH, Associate Professor, Medicine, Vanderbilt University Medical Center, Nashville, TN, during the NCCN 2022 Annual Conference.
Lowering the Screening Age
In version 1.2022 of the CRC screening guidelines, the age to initiate screening in average-risk individuals, regardless of race or sex, has been lowered from 50 years to 45 years, consistent with a US Preventive Services Task Force recommendation in May 2021, with the evidence to support this recommendation given a B grade.
“The impetus for this recommendation change is based on well-publicized trends in CRC incidence since the implementation of CRC screening in 1980,” said Dr Ness. The incidence of CRC in the United States in persons aged ≥50 years has decreased by approximately 40% over this period, accompanied by a small increase in incidence in persons aged <50 years. The cost-to-benefit ratio was deemed favorable for lowering the age for screening, he said.
The NCCN also recommends that individuals aged <45 years who present with alarming symptoms of CRC (ie, iron deficiency, rectal bleeding) also undergo screening colonoscopy.
For an individual with ≥1 first-degree relatives with CRC at any age, the recommendation to initiate screening colonoscopy remains at age 40 or 10 years before the earliest diagnosis of CRC in the family. Surveillance in this circumstance should be repeated every 5 years or, if positive, per the findings on colonoscopy.
The age for initiation of screening for individuals with second- and third-degree family members with CRC was also lowered from age 50 years to 45 years.
To achieve the best results, CRC screening should be performed as part of a population-based program and should include direct outreach to patients and clinic-focused interventions to increase screening rates, reduce the rate of mortality, and minimize disparities by race and ethnicity, according to the guidelines.
Changes to Surveillance Periods
Other than lowering the initial screening age, perhaps the most significant change to the NCCN guideline is the recommendation to extend the waiting period from 5 to 7 to 10 years before surveillance colonoscopy for patients with low-risk adenomas, defined as ≤2 polyps smaller than 1 cm at index colonoscopy. The basis for this recommendation is data showing that compared with patients with no adenoma, those with a low-risk adenoma did not have a significantly increased risk for CRC or related death, said Dr Ness.
“Although we decided to extend the surveillance period for patients presenting with 1 to 2 low-risk adenomas, we did not extend the surveillance period for patients with only low-risk sessile serrated polyps [SSPs] at index colonoscopy secondary to a perceived paucity of data,” he said. Therefore, the surveillance colonoscopy interval following the identification of only 1 or 2 low-risk SSPs remains at 5 years.
Surveillance colonoscopy interval following the identification of most high-risk adenomas/SSPs remains at 3 years.
Any individual with ≥10 adenomatous polyps at a single colonoscopy who does not have a polyposis syndrome is now recommended to have a repeat colonoscopy within 1 year, although data to inform this recommendation are limited.
“Another change to our surveillance guidelines was a shortening of our recommended surveillance interval for those patients with large colorectal adenomas or SSPs with either unfavorable risk characteristics for local recurrence or removed in piecemeal fashion from 12 to 6 months with the second surveillance colonoscopy recommended to occur 12 months later, even without evidence of recurrence at first surveillance colonoscopy,” Dr Ness said.
The initiation of surveillance colonoscopy remains at 8 years following the diagnosis of inflammatory bowel disease (IBD) colitis except in those patients with primary sclerosing cholangitis, in whom the surveillance interval is 1 year, or when family history recommendations supersede recommendations based on the duration of IBD. The surveillance colonoscopy interval in patients with IBD colitis remains at 1 to 3 years depending on measures of underlying CRC risk.