Doctors May Screen Stool Samples for Cancer
18 May, 2013
ISLAMABAD: Doctors may soon be able to save lives by checking stool samples for DNA evidence of cancer, researchers said .
A new stool test could one day help spot colorectal cancer, one of the most common cancers in the industrialized world, which now can usually be detected only with uncomfortable invasive procedures.
Scientists have long been looking for telltale signs in the stools of cancer sufferers that would allow for a less invasive test. A team of researchers, writing in the British journal The Lancet, reported that they found such signs in DNA in the stools.
When detected at the earliest stage, colon cancer is nearly 100 percent curable, doctors say. Hannes M. Mueller, from Austria's Medical University in Innsbruck, and colleagues were able to distinguish stools of patients with colorectal cancer from those of healthy patients by examining chemical changes to DNA found in the stool.
A gene known as SFRP2 was more likely to have undergone a chemical process called "methylation" in the stools of cancer sufferers than in those of healthy individuals.
"To our knowledge, SFRP2 methylation represents one of the most sensitive markers for identifying colorectal cancer ... in stool samples," wrote Martin Winschwendter, the study's principle investigator.
He said it still remained to be seen whether a group of markers could be found that would identify cancer at an early stage from stool samples.
Exact Sciences Corp., a small Massachusetts company, does have a test called Pregen-Plus that isolates human DNA from stool samples for early detection of colorectal cancer. However, Pregen-Plus, which has been available in the United States since last August, looks at different markers than those cited by researchers in the Lancet report.
The Exact Sciences test has shown to be a more accurate detector of cancer than the common fecal occult blood test, which only determines the presence of blood in stool -- a possible indicator cancer, but one that could have other causes.