This article is more than 5 years old. Information may no longer be current.
Novel assay aims to detect esophageal cancer in its earliest stages
Source: Johns Hopkins Medicine
Johns Hopkins University School of Medicine researchers have developed an assay designed to screen for esophageal cancer.
The test — called EsoBEE — involves specific epigenetic biomarkers that detect alterations in precancerous cells that line the esophagus.
“There is no screening method for esophageal cancer or its precancerous precursor conditions. However, this may soon change,” Stephen J. Meltzer, MD, professor of medicine and oncology at Johns Hopkins University School of Medicine, told HemOnc Today. “Our ultimate goal is to go from zero screening for esophageal cancer to 100% screening.”
HemOnc Today spoke with Meltzer about why this test may be superior to other screening approaches, the efficacy observed so far and plans for additional research.
Question: How was this test developed and how does it work?
Answer: We cannot perform endoscopy on everyone because it is not convenient. Endoscopy also is expensive and associated with complications, and it is only performed to evaluate symptomatic patients. I developed a test based upon my previous work in Barrett’s esophagus. With EsoBEE, the patient swallows a small capsule that has a long string attached to it. After the capsule makes its way down the esophagus and into the stomach — a process that takes approximately 1 minute — the gelatin coating on the capsule begins to dissolve, and it completely dissolves after 3 minutes. A 2-cm polyurethane sponge emerges from the capsule, still attached to the string. The string is gently pulled, and the sponge begins its return journey out of the mouth. The sponge comes into contact with the entire length and breadth of the esophagus on its way out, collecting genetic material along the way. The sponge is then sent to a company that performs simple epigenetic tests on the material to determine the patient’s risk for esophageal cancer or precancerous conditions, such as Barrett’s esophagus.
Q: What makes this test different from others?
A: It may allow us to differentiate between patients with a high methylation score and those with a low methylation score. We brought a product out into the market between 2013 and 2015. We had people send us their endoscopic biopsy samples and we ran methylation assays to give patients their prognostic scores. During this time, we identified a group of eight genes that factored into these scores. Patients were significantly more likely to progress to dysplasia or cancer if there was a higher methylation score.
Q: What efficacy has been observed so far?
A: The test appears accurate. The area under the curve for this sponge assay was approximately 0.85, which is considered good performance for a biomarker. We administered the test to 94 people, 85% of whom were able to swallow the capsule, with 100% successful sponge retrieval. Endoscopic evaluation of the patients after administration of the test has shown no evidence of bleeding, pain, trauma or other adverse reactions.
Q: What additional research is planned?
A: We plan to conduct research on larger groups of patients with Barrett’s esophagus and esophageal cancer to see if efficacy and accuracy continue to hold up. We also are making efforts toward bringing this test into the clinic and are studying other diseases for which this minimally invasive strategy could be used.
Q: When might something like this become available if proven safe and effective?
A: We are in a race with others conducting similar biomarker studies. Approval of one or more assays will occur soon — if not from me, then from one of my competitors. – by Jennifer Southall
For more information:
Stephen J. Meltzer, MD, can be reached at Johns Hopkins University School of Medicine, 1503 E. Jefferson St., Room 112, Baltimore, MD 21287; email: smeltzer@jhmil.edu.
Disclosure: Meltzer reports stock ownership in Capsulomics.