New guidelines for colorectal cancer screening released Two new tests added and prevention emphasized

Stool DNA and computed tomographic colonography (CTC) are now officially endorsed, albeit with some limitations, as standards for colorectal cancer screening, according to updated guidelines jointly issued by the American Cancer Society, the American College of Radiology and the US Multi-Society Task Force on Colorectal Cancer.

Furthermore, for the first time, the guidelines emphasize a preference for screening tests that detect adenomatous polyps as well as cancer prevention through polyp removal. These features, however, are not strong points of the two new tests.

A statement from the American Cancer Society said that this is the first time that guidelines from the American Cancer Society will express a strong preference for tests that can identify both polyps and cancer and lead to cancer prevention.

A professor of medicine and a chief of the Division of Gastroenterology at Oregon Health & Science University School of Medicine in Portland said that this will help consumers make decisions that can, quite literally, save their lives.

The joint committee recognized two broad categories of screening tests: fecal tests, which can identify the presence of cancer but are limited in the ability to prevent it, and structural examinations, which are favored for their ability to detect and remove precancerous and cancerous growths. The authors of the guidelines emphasize that physicians should discuss the limitations of noninvasive screening methods with patients. These methods are less likely than invasive procedures to prevent cancer, they must be repeated regularly to be effective and, if abnormal, they necessitate an invasive test (colonoscopy).

For the screening of average-risk people aged 50 years or older, the guidelines recommend the following for detecting both adenomatous polyps and cancer:

• Flexible sigmoidoscopy every five years,

• Colonoscopy every 10 years,

• Double-contrast barium enema every five years, or

• CTC every five years.

For primarily detecting cancer, the following tests, if they have high sensitivity, are recommended:

• Guaiac-based fecal occult blood test annually,

• Fecal immunochemical test annually, or

• Stool DNA test (the screening interval is uncertain, although some manufacturers recommend every five years).