Posted Friday, 5 February
DNA stool test may predict several cancers
A non-invasive screening test using DNA stool samples can detect not only colorectal cancer but also the common cancers above the colon - including pancreas, stomach, biliary and esophageal cancers, Mayo Clinic researchers say.
While gastrointestinal (GI) cancers account for about one in four cancer deaths, high cure rates can be achieved with early detection for each type - but currently only colorectal cancer is heavily screened in the adult population.
And while most people associate colorectal cancer screening with invasive colonoscopy, Mayo Clinic research has shown that stool DNA testing can identify both early-stage colorectal cancer and precancerous polyps.
Researchers are now studying the use of non-invasive stool DNA testing to detect lesions and cancer throughout the GI tract.
Using a stool test approach, researchers targeted DNA from cells that are shed continuously from the surface of these cancers. Also studied were 70 healthy patients.
Stool tests were performed on cancer patients and healthy controls by technicians unaware of sample source. As a result, the stool DNA test was positive in nearly 70% of digestive cancers but remained negative for all healthy controls, thus demonstrating the approach’s feasibility.
Stool DNA testing detected cancers at each organ site, including 65% of esophageal cancers, 62% of pancreatic cancers, and 75% of bile duct and gallbladder cancers. In this series, fully 100% of both stomach and colorectal cancers were detected.
Importantly, stool test results did not differ by cancer stage: early-stage cancers were just as likely to be detected as late-stage cancers.
“Historically, we’ve approached cancer screening one organ at a time,” notes Dr Ahlquist.
“Stool DNA testing could shift the strategy of cancer screening to multi-organ, whole-patient testing and could also open the door to early detection of cancers above the colon which are currently not screened. The potential impact of this evolution could be enormous.”
