The starting age was previously 50 years for most patients. However, for Black patients, the starting age was lowered to 45 years in 2005.
The new guidance brings the ACG in line with recommendations of the American Cancer Society, which lowered the starting age to 45 years for average-risk individuals in 2018.
However, the U.S. Preventive Services Task Force, the Multi-Specialty Task Force, and the American College of Physicians still recommend that CRC screening begin at the age of 50.
The new ACG guideline were published in March 2021 in the American Journal of Gastroenterology. The last time they were updated was in 2009.
The ACG said that the move was made in light of reports of an increase in the incidence of CRC in adults younger than 50.
“It has been estimated that [in the United States] persons born around 1990 have twice the risk of colon cancer and four times the risk of rectal cancer, compared with those born around 1950,” guideline author Aasma Shaukat, MD, MPH, University of Minnesota, Minneapolis, and colleagues pointed out.
“The fact that other developed countries are reporting similar increases in early-onset CRC and birth-cohort effects suggests that the Western lifestyle (especially exemplified by the obesity epidemic) is a significant contributor,” the authors added.
The new ACG guideline emphasize the importance of initiating CRC screening for average-risk patients aged 50-75 years. “Given that current rates of screening uptake are close to 60% (57.9% ages 50-64 and 62.4% ages 50-75), expanding the population to be screened may reduce these rates as emphasis shifts to screening 45- to 49-year-olds at the expense of efforts to screen the unscreened 50- to 75-year-olds,” the authors commented.
Now, however, the guideline suggests that the decision to continue screening after age 75 should be individualized. It notes that the benefits of screening are limited for those who are not expected to live for another 7-10 years. For patients with a family history of CRC, the guideline authors recommended initiating CRC screening at the age of 40 for patients with one or two first-degree relatives with either CRC or advanced colorectal polyps.
They also recommend screening colonoscopy over any other screening modality if the first-degree relative is younger than 60 or if two or more first-degree relatives of any age have CRC or advanced colorectal polyps. For such patients, screening should be repeated every 5 years.
For screening average-risk individuals, either colonoscopy or fecal immunochemical testing (FIT) is recommended. If colonoscopy is used, it should be repeated every 10 years. FIT should be conducted on an annual basis.
This is somewhat in contrast to recent changes proposed by the American Gastroenterological Association. The AGA recommends greater use of noninvasive testing, such as with fecal occult blood tests, initially. It recommends that initial colonoscopy be used only for patients at high risk for CRC.
For individuals unwilling or unable to undergo colonoscopy or FIT, the ACG suggests flexible sigmoidoscopy, multitarget stool DNA testing, CT colonography, or colon capsule. Only colonoscopy is a single-step test; all other screening modalities require a follow-up colonoscopy if test results are positive.
“We recommend against the use of aspirin as a substitute for CRC screening,” the ACG members emphasized. Rather, they suggest that the use of low-dose aspirin be considered only for patients aged 50-69 years whose risk for cardiovascular disease over the next 10 years is at least 10% and who are at low risk for bleeding.
To reduce their risk for CRC, patients need to take aspirin for at least 10 years, they pointed out.