Sponge in a capsule helps screen for Barrett's esophagus

Last Updated: 2015-02-05

By Reuters Staff

NEW YORK (Reuters Health) - A new method that allows for sampling of esophageal cells and assessment of trefoil factor 3 (TFF3) promises a less invasive approach for Barrett's esophagus screening, UK researchers say.

Most medical societies recommend endoscopic screening for patients with multiple risk factors for esophageal adenocarcinoma, and those found to have Barrett's esophagus usually enter an endoscopic surveillance program.

Dr. Rebecca C. Fitzgerald from the University of Cambridge, and colleagues in the BEST2 Study Group investigated whether a minimally invasive cell sampling device called the Cytosponge, coupled with immunohistochemical staining for TFF3 (a selective biomarker for Barrett's esophagus), could be used to identify patients in whom endoscopy is warranted.

The Cytosponge consists of a 30-mm polyurethane sponge in a capsule that's attached to a string. Patients swallow the capsule, which dissolves within the stomach after three to five minutes and is then retrieved by pulling on the string, thus collecting cells on its return passage along the esophagus. Analysis of the cell specimen for TFF3 expression provides an objective, binary read-out of the presence or absence of Barrett's esophagus (BE).

The study included 647 patients diagnosed with BE and 463 controls with dyspepsia and reflux symptoms.

Only a few of the patients (7.9%) and controls (3.9%) were unable to swallow the device. Of these, 11.8% were also unable to tolerate endoscopy.

Compared with diagnostic biopsy, the Cytosponge-TFF3 procedure was 79.9% sensitive and 92.4% specific for diagnosing BE, according to a report online January 29th in PLoS Medicine.

The sensitivity rose to 89.7% when patients who swallowed the device on a second occasion were included in the analysis. Sensitivity also increases with the length of the BE segment.

Thirty-four patients were positive by Cytosponge-TFF3 but negative for BE on endoscopy and biopsy.

When asked to rate the Cytosponge versus endoscopy, 34.5% of patients rated the procedures equally and 37.8% preferred the Cytosponge.

Adverse events were limited to oozing of blood from Cytosponge abrasion sites in 16.7% of patients; these abrasions were noted by the endoscopist and required no intervention.

"The Cytosponge-TFF3 test is safe and generally acceptable to patients with symptomatic reflux or dyspepsia undergoing investigation, and for those patients with BE undergoing surveillance," the researchers conclude.

"Risk stratification of TFF3-positive patients could be achieved through the addition of screening for further molecular markers in the same Cytosponge sample," they add, "and this strategy has the potential to significantly reduce the proportion of TFF3-positive patients who would require endoscopy."

Dr. Fitzgerald did not respond to a request for comments.

Data from this study were presented last November at the National Cancer Research Institute Cancer Conference in Liverpool, UK.

In 2013, the Medical Research Council licensed the Cytosponge technology to Covidien GI Solutions.

SOURCE: http://bit.ly/1zdh0R6

PLoS Med 2015;12:e1001780.