New test measures DNA methylation levels to predict colon cancer


An investigational DNA methylation test could alter the screening landscape for colorectal cancer, according to data presented at the American Association for Cancer Research special conference on Colorectal Cancer: Biology to Therapy.

Colorectal cancer is the third leading cause of cancer, and the second leading cause of cancer mortality. While celebrities continue to undergo public colonoscopies in an effort to increase awareness, only 60 percent of adults age 50 and older have undergone recommended screening, according to the Centers for Disease Control and Prevention ( CDC ).

Researchers at Mayo Clinic in Rochester have evaluated a test under development by Exact Sciences, a molecular diagnostics company in Wisconsin.
The test, which is not yet approved by the FDA, is conducted using a stool sample and works by detecting tumor-specific DNA alterations in cells that are shed into the stool from pre-cancerous or cancerous lesions.

In this first clinical validation study presented at the AACR conference, which included 1,100 patients, the researchers detected 64% of precancerous adenomas greater than 1 cm and 85% of cancers. Polyps over 1 cm are considered the most likely to progress. Furthermore, cancers and precancerous adenomas were detected equally well on both sides of the colon.

Colorectal cancer rate detection was 87% for cancers considered to be in the most curable stage ( stage I-III ) and 69% for the most advanced stage ( stage IV ). ( Xagena )

Source: American Association for Cancer Research, 2010

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