, a new study has found.
The study also found a similar low 3% rate of CRC detected at colonoscopy in both the younger and older adults.
“Our study suggests that adults ages 45-49 have a colorectal cancer risk that is similar to what we see in adults age 50,” senior author Jeffrey K. Lee, MD, MPH, gastroenterologist and research scientist at Kaiser Permanente Northern California Division of Research (DOR) in Oakland, California, said in a news release.
“The low number of cancers we found also provides support for initially offering younger adults a non-invasive test, like FIT, to determine which patients would benefit from a colonoscopy,” Lee noted.
Kaiser Permanente Medical Center
Dr. Jeffrey K. Lee
Timely and Important Question
“This study addresses a timely and important clinical question, namely, is FIT an acceptable screening modality in patients aged 45-49,” Ziad F. Gellad, MD, MPH, AGAF, professor of medicine, Duke University Medical Center, Durham, North Carolina, who was not involved in the study, said in an interview.
“The finding that FIT completion and yield in younger patients is similar to those aged 50 and above is good news because it supports the use of this screening modality in the younger cohort,” said Gellad, section chief, gastroenterology, Durham VA Health Care System.
Duke University
Dr. Ziad F. Gellad
The study was published online in Annals of Internal Medicine.
In 2021, the US Preventive Services Task Force lowered the age to start CRC screening from 50 to 45 years, in response to studies showing an increased rate of CRC in adults aged 45-49 years.
The decision to start CRC screening at age 45 was made based on modeling studies, which are dependent on assumptions, co-first author Theodore R. Levin, MD, who is also a gastroenterologist and research scientist at Kaiser Permanente DOR, said in an interview.
“We thought it was important to collect real-world data on the experience of screening in this age group. We had no basis to know whether younger people would take up screening or if the yield of screening would be sufficiently high to warrant starting screening in this age group,” said Levin.
The researchers compared FIT screening completion and outcomes in 213,928 patients aged 45-49 years and 53,804 patients aged 50 years who received a FIT kit for the first time. The patients were from Kaiser Permanente Northern California, Washington, and Colorado.
Overall, FIT completion rates were slightly higher in the younger adults than in the 50-year-olds (38.9% vs 37.5%; adjusted risk ratio [aRR], 1.05), although the younger patients from Colorado were substantially less apt to complete a FIT (30.7% vs 40.2%; aRR, 0.77).
In the overall 45- to 49-year age group, 3.6% of adults had a positive FIT result, only slightly lower than the 4% positivity rate in the 50-year age group (aRR, 0.91).
About two thirds of adults in both groups who had a positive FIT result went on to have a colonoscopy within 3 months of receiving the test result.
Adenoma detection during colonoscopy was slightly lower in the younger than in the older group (58.8% vs 67.7%; aRR, 0.88). However, yields were similar for adenoma with advanced histology (13.2% vs 15.9%; aRR, 0.86), polyp with high-grade dysplasia (3.4% vs 5.1%; aRR, 0.68), sessile serrated lesion (10.3% vs 11.7%; aRR, 0.92), and CRC (2.8% vs 2.7%; aRR, 1.10).