A Prospective, Multicenter Study to Evaluate a Novel, Nonendoscopic Screening Device for Barrett's Esophagus in the Community Setting

Abstract

Most Barrett's esophagus (BE) cases are undiagnosed; this condition can progress to esophageal adenocarcinoma, which has a very poor prognosis unless detected early. We have previously developed a Medicines and Healthcare Products Regulatory Agency-approved CytoSponge test coupled with immunocytologic assessment of a biomarker TFF3 to diagnose BE nonendoscopically. The Cytosponge is a gelatin encapsulated sponge on a string which is swallowed, expands in the stomach, and is then withdrawn, sampling cells along the esophagus. The aims of the study were to assess the applicability of the test to primary care, the participant experience of the CytoSponge, and the accuracy of the test. METHODS: A prospective, multicenter, primary care study identified individuals with a history of reflux symptoms from 100,688 practice drug prescribing records. Eligible participants were invited for testing with the Cytosponge in their own practice. At this appointment, as well as on days 7 and 90, participants reported their experience of the procedure (visual analog scale scored from 0 to 10, worst to best experience) and filled in validated questionnaires to assess any anxiety induced (STAI-6 and Impact of Events Scale). The Cytosponge samples were processed to a paraffin block and then immunostained for Trefoil Factor 3 to diagnose BE. All patients were invited to endoscopy in secondary care as the diagnostic gold standard. RESULTS: Of the 506 patients eligible, 501 (99%, 2 were too anxious and 3 could not swallow the device; median age, 62 years; M:F ratio, 1:1.2) swallowed the Cytosponge. The median body mass index of 29.4 (range, 26.2-32.9) indicated that most participants were overweight and >45% were obese. There were no serious adverse events related to the screening test. The median experience score was 7 (interquartile range, 5-8). Any anxiety returned to low levels by day 7 and Impact of Events Scale suggested that <4.5% displayed significant distress. Of the 501 patients screened, 15 (3%) had an endoscopic diagnosis of BE (>1 cm circumferential [C1], median C4M5) with intestinal metaplasia. The sensitivity and specificity of the test compared with gastroscopy was 73.3% and 93.5% for <1 cm circumferential (C1) and 90.0% and 93.5% for