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ORLANDO -- A noninvasive "electronic nose" device that analyzes exhaled volatile organic compounds showed promise as a screening tool for Barrett's esophagus, a researcher reported here.
In a study comparing breath samples from patients with untreated Barrett's esophagus and those without Barrett's esophagus undergoing endoscopy for other reasons, a predictive model found that the sensitivity of the test was 89%, specificity was 71%, accuracy was 79%, and area under the curve was 0.81, according to Kavel Visrodia, MD, of the Mayo Clinic in Rochester, Minnesota.
Action Points
- Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
"The prognosis for advanced esophageal adenocarcinoma (EAC) remains dismal. However, while persons with Barrett's esophagus (the only known precursor of EAC) undergo surveillance, over 90% of EACs are diagnosed outside of surveillance programs, which suggests that current screening and surveillance programs are inadequate," Visrodia reported during a poster session at the World Congress of Gastroenterology at ACG2017.
Moreover, current approaches to screening for Barrett's esophagus are intrusive and costly.
In order to develop a more acceptable, inexpensive, portable means of screening, Visrodia's group used the second-generation electronic nose, which analyzes breath samples over a period of 5 minutes. The breath sample is circulated over a metal-oxide sensor array, and volatile organic compounds in the sample cause oxidation-reduction reactions in the sensor.
In turn, those reactions lead to changes in circuit conductance and temperature within the sensor, he explained.
The Aeonose device then measures these changes, creating a three-dimensional digital signature of the sample, which is then uploaded to an artificial neural network for pattern recognition analysis.
The patients with Barrett's esophagus were required to have at least 1 cm of columnar mucosa from the gastroesophageal junction with histopathologic confirmation of intestinal metaplasia. The non-Barrett's group could not have any history of the disorder.
The Barrett's group included 27 patients, while the non-Barrett's group consisted of 31 individuals. Mean age in the Barrett's group was 67, while age in the non-Barrett's group was 57. In both groups, more than 70% were men. Alcohol and tobacco use was similar in the groups, as were rates of hiatal hernia and gastroesophageal reflux.
The positive predictive value of the test was 0.73 and negative predictive value was 0.88. The Matthews correlation coefficient was 0.60.
In addition, the recruitment rate was 99%, suggesting that the device is acceptable to patients. The Aeonose device therefore may be useful as a screening tool to identify patients with Barrett's esophagus who should undergo surveillance for EACs, according to Visrodia.
Further work is ongoing to improve the model and the efficiency of the test, and a validation study is underway.
Primary Source
World Congress of Gastroenterology at ACG2017
Visrodia K, et al "Developing a screening test for Barrett's esophagus using electronic nose device analysis of exhaled volatile organic compounds" World Congress of Gastroenterology at ACG2017; Abstract P1078.