ROCKVILLE, Maryland—Every man and woman age 50 or older with an average
risk of colorectal cancer should be screened for colorectal cancer
periodically, according to a new and strong recommendation from the US
Preventive Services Task Force (USPSTF). The panel’s report also said
screening for the disease at an earlier age in people at high risk is a
reasonable practice.

"The USPSTF found fair to good evidence that several screening methods are
effective in reducing mortality from colorectal cancer," the report said.
"The USPSTF concluded that the benefits from screening substantially outweigh
potential harms, but the quality of evidence, magnitude of benefit, and
potential harms vary with each method."

The panel is an independent group of experts sponsored by the Agency for
Healthcare Research and Quality (AHRQ) that makes recommendations across the
prevention spectrum. Its recommendations do not represent federal policy but
are widely accepted within medicine. It made its new recommendations after
reviewing an updated evaluation of the scientific literature pertaining to
colorectal screening techniques.

"The USPSTF found good evidence that periodic fecal occult blood testing (FOBT)
reduces mortality from colorec-tal cancer and fair evidence that
sigmoidoscopy alone or in combination with FOBT reduces mortality," the
report said.

Although the panel did not find direct evidence that colonoscopy reduced
colorectal cancer mortality, its efficacy "is supported by its integral role
in trials of FOBT, extrapolation from sigmoi-doscopy studies, limited
case-control evidence, and the ability of colonoscopy to inspect the proximal
colon."

Double-contrast barium enema offers an alternative to whole-bowel
examination, but its sensitivity is below that of colonoscopy, and no direct
evidence supports its efficacy in reducing mortality, the USPSTF concluded.

It also found insufficient evidence that newer screening techniques, such
as computed tomographic colography (also known as virtual colonoscopy),
improve the outcomes of patients with colorectal cancer. CT colography has
proven relatively sensitive and specific in research settings—85% to 90%—but
recent reports suggest a lower accuracy when performed by less experienced
practitioners.