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Sponge Capsule Test Aids Barrett’s Diagnosis
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A test that captures genetic biomarkers from the esophagus using a small sponge can help identify signs of Barrett’s esophagus leading to the early detection of esophageal cancer, according to research published in Clinical Cancer Research.
For the test, a patient swallows a small capsule attached to a string, known as the EsophaCap (CapNostics). Once it reaches the stomach, the capsule dissolves revealing a two-centimeter sponge that collects genetic material when it is pulled back out through the mouth. The sponge is then sent away for genetic testing that can help determine the patient’s risk for esophageal cancer.
“Early detection is the whole ballgame when it comes to esophageal cancer,” Stephen J. Meltzer, MD, professor of medicine and oncology at the Johns Hopkins School of Medicine, said in a press release. “Patients have a much better chance to treat it — or even prevent it — if they know their risk. We believe this little sponge can bring easy and inexpensive screening to people around the world.”
Meltzer and colleagues conducted a prospective cohort study of 80 patients and included a training set (n = 52) and a test set (n = 28). Once they extracted the sponge, researchers used a qualitative methylation specific polymerase chain reaction assay to assess methylation levels of eight biomarkers that they have previously used to diagnose BE.
Investigators built a model for BE diagnosis that had a sensitivity of 94.4% (95% CI, 71%–99%) and specificity of 62.2% (95% CI, 44.6%–77.3%) in the training set, and a sensitivity of 78.6% (95% CI, 48.8%–94.3%) and specificity of 92.8% (95% CI, 64.1%–99.6%) in the test set.
Meltzer and colleagues reported that 85% of patients were able to swallow the capsule, and of those patients, nearly half would be diagnosed with BE, a rate much higher than that of the general population in the United States. However, they said most of the patients in the study were being treated for gastrointestinal symptoms, which could explain the higher rates of BE.
Endoscopic evaluation after the test revealed no evidence of bleeding, trauma or other adverse events, according to the press release.
Meltzer said a reliable test for BE could make a big difference in catching esophageal cancer.
“It's actually possible to miss early cancerous cells using endoscopy with biopsy and most patients with Barrett's don't ever undergo endoscopy,” Meltzer said in the release. “Right now, we're confident that we have the tools to identify this type of cancer. But we previously lacked a way to collect enough genetic material to confidently determine a patient's diagnosis. We believe that EsophaCap now provides a solution to this serious problem.” – by Alex Young
Disclosures: The authors report no relevant financial disclosures.
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