Albert Siu, MD, MSPH
The United States Preventative Services Task Force (USPSTF) recommends screening for colorectal cancer (CRC) using traditional colonoscopy or one of 7 tests at various frequencies for all patients aged 50 to 75, according to final guidance issued by the Task Force.
The recommendation to screen all patients, which was given an A Grade, was based upon an analysis of the risks and benefits associated with the various procedures. Across analyses, CRC screening was associated with a decrease in mortality.
Screening for adults between the ages of 76 and 85 is considered voluntary and should take into account the patient’s overall health, if they are healthy enough to undergo treatment should a cancer be detected, and prior colorectal cancer screening history.
“The Task Force strongly recommends screening adults ages 50 to 75 for colorectal cancer, as it reduces the risk of dying from the disease,” said USPSTF immediate past chair Albert Siu, MD, MSPH, from Mount Sinai. “Evidence convincingly shows screening for colorectal cancer works, but not enough people are taking advantage of this highly effective service.”
The updated recommendation reviewed the safety and efficacy of colonoscopy, flexible sigmoidoscopy, computed tomography (CT) colonography, the guaiac-based fecal occult blood test, the fecal immunochemical test (FIT), the multitargeted stool DNA test (FIT-DNA), and the methylated SEPT9
DNA test as possible methods for the detection of colorectal cancer.
The guaiac-based fecal occult blood test should be completed on a yearly basis if the person is not in a surveillance program. According to the USPSTF’s model estimates, approximately 22 CRC deaths would be averted per every 1000 screened with this method.
FIT, which offers improved accuracy over the guaiac-based fecal occult blood test, would also be completed yearly and would prevent approximately 22 deaths per every 1000 screened.
FIT-DNA testing can be done yearly or every 3 years, according to the manufacturer. On a yearly basis, the method would prevent 23 deaths, and when completed every 3 years, the test would prevent 20 deaths. The test may result in more false-positive results but it provides increased sensitivity per single screening test than FIT.
Among the direct visualization tests, colonoscopy was suggested every 10 years. The method would avert 24 CRC deaths per every 1000 screened and would also yield the most life-years gained of all the other screening methods.
CT colonography would prevent 22 deaths when testing every 5 years.
Flexible sigmoidoscopy testing alone would avert 20 deaths when completed every 5 years. However, flexible sigmoidoscopy testing every 10 years combined with FIT every year would prevent an additional 3 deaths per every 1000 screened.
The methylated SEPT9
DNA test was found to have less than 50% sensitivity for the detection of colorectal cancer, leading to limited evidence supporting its use.
Different levels of evidence support the effectiveness of each of the screening methods. The choice for which screening test to take is up to the patient and the physician.
“There are multiple screening options for colorectal cancer that reduce the risk of dying from the disease. We encourage people to choose the best option for them, in consultation with their clinician,” said former USPSTF member Douglas K. Owens, MD, MS, from the Palo Alto Health Care System.
Judy Yee, MD, chair of the American College of Radiology (ACR) Colon Cancer Committee, said that increased access to screening has the potential to drastically reduce the amount of deaths from CRC each year.
“If more patients come in for screening, we would be able to identify those patients with the significant precursor polyp and send them to have them removed,” Yee said in an interview with OncLive
. “Additionally, if more people undergo virtual colonoscopy, we would be able to identify colorectal cancers at an earlier stage when they are more likely curable.”
Yee said that more people are still getting “traditional” colonoscopies compared with virtual colonoscopies, but with about one-third who are eligible for screening not being tested, it is clear that other options that “more appealing for patients” are needed.
By recommending more testing methods such as virtual colonoscopy, which is less invasive and does not require sedation, the USPSTF hopes that more people would get this potentially life-saving screening.
“About one-third of eligible adults in the United States have never been screened for colorectal cancer, and offering choice in colorectal cancer screening strategies may increase screening uptake,” according to the USPSTF statement.
US Preventive Services Task Force. Screening for Colorectal Cancer: US Preventive Services Task Force Recommendation Statement [published online June 15, 2016]. JAMA. doi:10.1001/jama.2016.5989.