Detecting Digestive Cancers with Improved DNA Stool Test
Posted Jun 02 2009 1:00pm
It's Digestive Disease Week 2009 in Chicago. The wires are rolling with news releases relating to disease diagnosis in all sorts of uncomely organs, including an improved DNA stool test that helps detect wide-ranging digestive tract cancers as well as colon cancer.
Tess and I were just looking at The Human Body Book (from a Body World exhibit) and we were almost unnaturally fascinated with pictures of intestinal villi, cross-sections of the pancreas, diagrams of "liver architecture," layers of the colon wall, and so forth. Once upon a time, both of us would have gladly passed over "news" about a stool test with an "eeew" sound and a pinched brow.
Hmm. That image just transported me back in time. I remember my great-grandmother, Mimi, asking me to slice a thick callus off one of her toes with a razor blade. I was about 13 or 14 years old. She saw my face scrunch up and a sound of revulsion start to emerge and quickly cut me off with a matter-of-fact tone of voice and words: "This is life--and you can't pull back from real life if you want to grow up."
Sheesh. I felt dressed down. I steadied my hand to ensure I didn't cut too deep. I'll never forget that moment in my favorite grandmother's room, overlooking her garden, which was always filled with camelias, fuschia, and bird of paradise flowers in Santa Monica, California.
The researchers studied 70 patients with cancers throughout the digestive tract. Besides colon cancer, the study looked at throat, esophagus, stomach, pancreatic, bile duct, gallbladder and small bowel cancers to determine if gene mutations could be detected in stool samples. Using a stool test approach developed at Mayo Clinic, 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. The stool DNA test was positive in nearly 70 percent 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 percent of esophageal cancers, 62 percent of pancreatic cancers, and 75 percent of bile duct and gallbladder cancers. In this series, 100 percent 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.
"It’s very exciting to see this level of sensitivity for digestive cancer detection in our first look at this test application,” says Dr. Ahlquist, “Historically, we’ve approached cancer screening one organ at a time. 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.”
Shifting cancer screening to a more holistic approach that supports earlier detection of digestive diseases (and earlier interventions--whether with pharmaceuticals, nutritional regimes, or integrative protocols) is really quite good news.
If you are over 50, check out some of the Mayo videos (high-speed Internet helps) and also consider asking your physician about the new and improved DNA stool testing. It could save your life!