The National Comprehensive Cancer Network® (NCCN®) Clinical Practice Guidelines in Oncology: Colorectal Cancer Screening have recently incorporated significant changes, reflecting recommendations that will spare some patients unnecessary interventions and, in other cases, detect cancer earlier. The updated recommendations were presented during the virtual NCCN 2022 Annual Conference by Reid M. Ness, MD, MPH, Assistant Professor of Medicine at Vanderbilt-Ingram Cancer Center, Nashville.
“The first and most significant change in our guidelines was a lowering of the initial screening age for average-risk individuals from 50 to 45. The second biggest change is the recommendation to extend the surveillance period from 5 to 7 years to 10 years for patients with only one to two small tubular adenomas at the index colonoscopy,” Dr. Ness explained.
In other changes, the NCCN Panel now recommends lowering the age for first screening in persons with second- and third-degree relatives with colorectal cancer from 50 to 45; shortening the timing to the first surveillance exam to 6 months after resection of large adenomas or sessile serrated polyps with unfavorable characteristics or removed piecemeal; and shortening the time to first surveillance to 1 year for patients found to have ≥ 10 adenomas or sessile serrated polyps at a single colonoscopy.
Lowering the Screening Age
“The impetus for lowering the initial screening age is based on well-publicized trends in colorectal cancer incidence since the implementation of colorectal cancer screening in 1980,” Dr. Ness said.
Reid M. Ness, MD, MPH
During this period, the 40% overall drop in colorectal cancer incidence in the United States has been accompanied by a rising incidence in adults younger than age 50. Modeling exercises have shown “small but significant” increases in life-years gained from colorectal cancer screening beginning at age 45, he said.
Some screening experts have argued that the cost of initiating screening before age 50 would result in “unacceptably high” absolute costs. “Despite these concerns, our committee felt that the cost-to-benefit trade-off was acceptable,” Dr. Ness said.
“All U.S. colorectal cancer screening guidelines have been brought into accord,” he added. The same recommendation was subsequently made by the U.S. Preventive Services Task Force in May 2021 and the Multi-Society Task Force on Colorectal Cancer Screening in November 2021.
Since half of all patients who will present with colorectal cancer before age 50 do so before they reach age 45, the NCCN also recommends that all patients presenting with symptoms suggestive of a possible diagnosis of colorectal cancer, such as iron deficiency and rectal bleeding, be evaluated with colonoscopy in a timely fashion, Dr. Ness added.
The committee also considered whether initial screening age should be even lower for average-risk non-Hispanic Black patients but determined that, based on modeling, age 45 is appropriate for all sex- and race-based groups.
Extending Surveillance Period to 10 Years
“The recommendation to extend the surveillance period after the findings of a low-risk adenoma is based upon very strong cohort data,” Dr. Ness said. Unlike for patients with high-risk lesions, colorectal cancer risk in patients with one or two small tubular adenomas is not significantly increased over persons with no polyps at all on baseline colonoscopy, a number of large studies have shown.
“We kept the recommended surveillance interval for patients with three or more low-risk adenomas and sessile serrated polyps, and most higher-risk adenomas and sessile serrated polyps, at 3 years. We also continue to recommend consideration of genetic testing for a polyposis syndrome in all patients with ≥ 10 adenomas or sessile serrated polyps on a single colonoscopy or with a lifetime cumulative incidence of ≥ 20. In contrast, we now recommend that any person with ≥ 10 polyps at colonoscopy who does not have a polyposis syndrome have repeat colonoscopy within 1 year,” said Dr. Ness.
Other Recommendations
The surveillance interval has been shortened for patients with large (≥ 1 cm) adenomas and sessile serrated polyps with either unfavorable risk factors for local recurrence or removed in piecemeal fashion. The NCCN now recommends the first surveillance colonoscopy at 6 months, rather than 12, with the second occurring 12 months later, even without evidence of recurrence at the first surveillance examination.
Individuals with a first-degree relative with colorectal cancer or endometrial cancer diagnosed before age 50, or with synchronous or metachronous Lynch syndrome–related cancers (regardless of age), should undergo genetic evaluation. Otherwise, for persons with a first-degree relative with colorectal cancer, the NCCN recommends colonoscopy beginning at age 40, or 10 years before the earliest diagnosis of colorectal cancer in the family, with surveillance at least every 5 years. Studies show a 10-year earlier shift in diagnosis in persons with this family history.
“After much discussion, our committee continued to only recommend colonoscopy screening beginning at age 45 for persons with colorectal cancer limited to second- and third-degree relatives,” Dr. Ness said.
Finally, for adults whose first-degree relatives have confirmed advanced adenoma or advanced sessile serrated polyps at any age, the recommendations are similar to those for patients with an affected first-degree relative with colorectal cancer.
