DocGuide

The US Preventive Services Task Force (USPSTF) found convincing evidence that colorectal cancer screening substantially reduces deaths from the disease among adults aged 50 to 75 years and that not enough adults in the United States are using this effective preventive intervention.

About one-third of eligible adults in the United States have never been screened for colorectal cancer, according to a report that appears in the June 21 issue of JAMA.

To update its 2008 recommendation, the USPSTF reviewed the evidence on the effectiveness of several screening strategies, including colonoscopy, flexible sigmoidoscopy, computed tomography colonography, the guaiac-based fecal occult blood test, the fecal immunochemical test, and the multitargeted stool DNA test, in reducing the incidence of and mortality from colorectal cancer or all-cause mortality; the harms of these screening tests; and the test performance characteristics of these tests for detecting adenomatous polyps, advanced adenomas based on size, or both, as well as colorectal cancer.

The USPSTF also commissioned a comparative modelling study to provide information on optimal starting and stopping ages and screening intervals across the different available screening methods.

The USPSTF found convincing evidence that screening for colorectal cancer with several different methods can accurately detect early-stage colorectal cancer and adenomatous polyps. Although single test performance is an important issue in the detection of colorectal cancer, the sensitivity of the test over time is more important in an ongoing screening program.

The USPSTF found convincing evidence that screening for colorectal cancer in adults aged 50 to 75 years reduces colorectal cancer mortality.

The USPSTF found no head-to-head studies demonstrating that any of the screening strategies it considered are more effective than others, although the tests have varying levels of evidence supporting their effectiveness, as well as different strengths and limitations.

The benefit of early detection of and intervention for colorectal cancer declines after age 75 years. Among older adults who have been previously screened for colorectal cancer, there is at best a moderate benefit to continuing screening during the ages of 76 to 85 years. However, adults in this age group who have never been screened for colorectal cancer are more likely to benefit than those who have been previously screened. The time between detection and treatment of colorectal cancer and realisation of a subsequent mortality benefit can be substantial. As such, the benefit of early detection of and intervention for colorectal cancer in adults aged 86 years and older is at most small. To date, no method of screening for colorectal cancer has been shown to reduce all-cause mortality in any age group.

The harms of screening for colorectal cancer in adults aged 50 to 75 years are small. The majority of harms result from the use of colonoscopy, either as the screening test or as follow-up for positive findings detected by other screening tests. The rate of serious adverse events from colorectal cancer screening increases with age. Thus, the harms of screening for colorectal cancer in adults aged 76 years and older are small to moderate.

The USPSTF recommends screening for colorectal cancer starting at age 50 years and continuing until age 75 years, and the decision to screen for colorectal cancer in adults aged 76 to 85 years should be an individual one, taking into account the patient's overall health and prior screening history (

SOURCE: JAMA