SAN DIEGO — Mayo Clinic researchers were among international experts who presented findings at Digestive Disease Week 2019, the world's largest gathering of physicians, researchers and industry leaders in gastroenterology and related fields.
Digestive Disease Week 2019 was held May 18–21 in San Diego. The meeting featured 5,400 lectures, poster presentations and oral abstract presentations. Mayo researchers were available to discuss their studies and findings with reporters during the conference.
Among the more than 40 Mayo studies and presentations featured were:
"Pancreatic Cancer Detection by Plasma Assay of Novel Methylated DNA Markers: A Case-Control Study"
Embargoed until presentation on Monday, May 20, from noon to 2 p.m. PDT.
Early detection of pancreatic cancer can lead to improved long-term survival. The only available blood-based biomarker is unreliable for detecting early-stage carcinoma, but this Mayo Clinic study, conducted in collaboration with Exact Sciences Corporation, of Madison, Wisconsin, demonstrates that a new blood-based DNA marker can accurately detect pancreatic cancer across all stages.
"A blood-based biomarker like the one described in this study, once validated prospectively, could be clinically used for early detection in patients at high risk for developing pancreatic cancer," says Shounak Majumder, M.D., a Mayo Clinic gastroenterologist and the study's lead author.
Using blood samples from 340 patients — 170 pancreatic cancer patients and 170 normal controls — the study found that a panel of DNA markers in combination with carbohydrate antigen 19-9 (CA 19-9) detected 92% of all cancers, including 79% of stage 1 cancers. The combination of these DNA markers with CA 19-9 significantly improves cancer detection, compared to CA 19-9 alone. A prospective study to validate these results is underway at Mayo Clinic.
"Noninvasive Screening for Barrett's Esophagus Using an Electronic Nose"
Embargoed until poster presentation on Saturday, May 18, from noon to 2 p.m. PDT.
Esophageal adenocarcinoma is the most common type of esophageal cancer in the U.S., and it typically isn't diagnosed until advanced stages. The only known precursor for the disease is Barrett's esophagus, which also goes undetected as an asymptomatic condition that requires an endoscopy for diagnosis.
This Mayo Clinic study evaluated a new screening method for Barrett's esophagus, using an electronic nose device, called an "e-nose," to analyze the patient's exhaled breath. The device can detect volatile organic compounds associated with Barrett's esophagus. The study showed that a distinctive signature for Barrett's esophagus can be detected with fairly high accuracy, according to lead author Juan Reyes Genere, M.D., a Mayo Clinic gastroenterology fellow.
Researchers prospectively invited patients with established Barrett's esophagus and controls without Barrett's esophagus to provide breath samples prior to routine, clinically indicated endoscopy. They found that the accuracy was high, especially among patients taking a high-dose proton pump inhibitor, an acid reduction medicine.
"It was surprising to see the dosage of acid-reducing medication made a significant difference to the accuracy," Dr. Reyes Genere says. "Stomach acid is a protective barrier that kills bacteria entering our gastrointestinal tract. Reducing stomach acid permits more bacterial colonization in the gut, thereby enhancing the volatile organic compound signatures."
This effect was noticeably reduced in patients on low-dose medications, he says. The research team is now testing this model in blinded samples.
"Endoscopic Management of Late Dumping Syndrome: International Series and Proposed Management Strategy"
Embargoed until Tuesday, May 21, at 3 p.m. PDT.
Dumping syndrome is a condition that frequently occurs after Roux-en-Y gastric bypass surgery, in which patients experience various symptoms after eating a meal, including low blood sugar, palpitation and diaphoresis. It can severely affect quality of life and at times requires reversal of the bariatric surgery.
Mayo Clinic researchers reviewed a multicenter series of patients who were treated for refractory dumping syndrome, with the goal of proposing a multidisciplinary management strategy for such patients. The study found that a minimally invasive endoscopic treatment option is safe and effective at improving symptoms and reducing rates of surgical revision.
"Before these findings, a large therapeutic gap between medications and reversal of their gastric bypass surgery existed for these patients," says Eric Vargas, M.D., a Mayo Clinic gastroenterology fellow. "We believe our study adds a much-needed treatment alternative using endoscopy for patients who have failed medications but are concerned about undergoing gastric bypass reversal."
"Sensitivity of Computerized Tomography During Prediagnostic Course of Pancreatic Ductal Adenocarcinoma"
Embargoed until May 18 e-poster tour, from 1:20 to 1:50 p.m. PDT. Other presentations are May 20 from 11:45 a.m. to 12:30 p.m. PDT, and poster on May 20 from noon to 2 p.m. PDT.
Early detection of pancreatic ductal adenocarcinoma (PDAC) offers the best hope for improved disease survival. Though strategies are being developed to test and screen asymptomatic high-risk patients, it's unclear whether routine imaging, such as CT scans, is effective.
Mayo Clinic researchers retrospectively looked at high-resolution CT scans that were performed on patients for other reasons prior to pancreatic ductal adenocarcinoma diagnosis. According to Suresh Chari, M.D., a Mayo Clinic gastroenterologist, findings suggestive of pancreatic ductal adenocarcinoma were seen on CT scans in a majority of patients six months prior to diagnosis, when patients were asymptomatic.
Dhruv Singh, M.B.B.S., a Mayo Clinic gastroenterology research fellow, says the findings suggest that early CT screening for asymptomatic high-risk individuals may identify nonmetastatic disease, improving patient survival.
"Pancreatic cancer is the third-leading cause of cancer-related deaths in the U.S., with an overall five-year survival rate of 9%," Singh says. "The mortality is high because by the time the cancer clinically presents, it is advanced and difficult to surgically resect. Our study shows that CT imaging, when used in the target population, can pick up subtle changes in the pancreas before PDAC becomes symptomatic."
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