Gastrointestinal (GI) cancers account for approximately one in four cancer deaths. While high cure rates can be achieved with early-stage detection for each type, only colorectal cancer is currently screened at the population level.
Most people associate colorectal cancer screening with invasive colonoscopy, but previous 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 noninvasive stool DNA testing to detect lesions and cancer throughout the GI tract.
"Patients are often worried about invasive tests like colonoscopies, and yet these tests have been the key to early cancer detection and prevention," says David Ahlquist, M.D., Mayo Clinic gastroenterologist and lead researcher on the study. "Our research team continues to look for more patient-friendly tests with expanded value, and this new study reveals an opportunity for multi-organ digestive cancer screening with a single noninvasive test."
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."
In October 2008, this Mayo Clinic research team published results of a multicenter study using first-generation stool DNA testing. In the seven-year, multicenter study (Ann Intern Med 2008;149:441-50), researchers found that the first-generation stool DNA tests were better than fecal blood tests for detecting cancer and precancerous polyps of the colon. In January 2009 (Gastroenterology 2009;136:459-70), Mayo researchers published some technical improvements that nearly doubled the sensitivity of stool DNA testing for detecting premalignant polyps and increased cancer detection to about 90 percent, which is the approximate rate of detection observed for CT colonography.
Researchers hope that the next generation tests will have significant improvements in accuracy, processing speed, ease of patient use and affordability. "We anticipate that next generation tests will also be able to predict the tumor site, which will help physicians direct diagnostic studies and minimize unnecessary procedures," says Dr. Ahlquist.
Dr. Ahlquist and Mayo Clinic have a financial interest related to technology studied in this research.
Other researchers from Mayo Clinic include: Hongzhi Zou, M.D., Ph.D; Jonathan Harrington; William Taylor; Mary Devens; Xiaoming Cao, M.D.; Russell Heigh, M.D.; Yvonne Romero, M.D.; Suresh Chari, M.D.; Gloria Petersen, Ph.D.; Lewis Roberts, M.B.Ch.B., Ph.D.; Jan Kasperbauer, M.D.; Julie Simonson; David I. Smith, Ph.D.; and Thomas Smyrk, M.D.
Mayo Clinic's Division of Gastroenterology and Hepatology has been ranked #1 in the U.S. News & World Report Honor Roll of Top Hospitals since the rankings began 19 years ago.
About Mayo Clinic
Mayo Clinic is the first and largest integrated, not-for-profit group practice in the world. Doctors from every medical specialty work together to care for patients, joined by common systems and a philosophy of "the needs of the patient come first." More than 3,300 physicians, scientists and researchers and 46,000 allied health staff work at Mayo Clinic, which has sites in Rochester, Minn., Jacksonville, Fla., and Scottsdale/Phoenix, Ariz. Collectively, the three locations treat more than half a million people each year. To obtain the latest news releases from Mayo Clinic, go to www.mayoclinic.org/news. For information about research and education, visit www.mayo.edu. MayoClinic.com (www.mayoclinic.com) is available as a resource for your health stories.
Amy Tieder | EurekAlert!
Biofilm discovery suggests new way to prevent dangerous infections
23.05.2017 | University of Texas at Austin
Another reason to exercise: Burning bone fat -- a key to better bone health
19.05.2017 | University of North Carolina Health Care
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...
23.05.2017 | Event News
22.05.2017 | Event News
17.05.2017 | Event News
23.05.2017 | Physics and Astronomy
23.05.2017 | Life Sciences
23.05.2017 | Medical Engineering