Cancer of the oesophagus claims more than 400 000 lives
around the world each year. With no efficient, reliable method of screening for
the disease, by the time symptoms become apparent, it’s often too late to save
A Johns Hopkins researcher who has devoted his career to the
detection and prevention of oesophageal cancer published a paper in the
journal Clinical Cancer Research that he says could finally result in
simple and inexpensive screening for the deadly disease.
In the article, gastroenterologist Stephen Meltzer, a
professor of medicine and oncology at the Johns Hopkins University School of
Medicine, along with a team of researchers, clinicians and biomedical engineers
describe a test – the “EsophaCap” – that uses specific genetic biomarkers to
detect dangerous changes in the cells that line the inside of the oesophagus.
Previous studies have demonstrated Meltzer’s biomarkers’
ability to detect Barrett’s oesophagus.
The principle behind the EsophaCap is simple, says Meltzer.
The patient swallows a small capsule that has a long string attached to it.
After the capsule makes its way down the oesophagus and into the stomach, the
gelatin coating on the capsule begins to dissolve.
From that capsule emerges a 2-centimeter polyurethane
sponge, still attached to the string, much of which still hangs from the
The screener gently pulls the string and the sponge begins
its return journey, out of the stomach, into the oesophagus and, finally, out
of the patient’s mouth.
As it makes its way up, the sponge comes into contact with
the entire length and breadth of the oesophagus, collecting genetic material
all along the way. Then, as the sponge nears the top, the screener gives a
final gentle tug, popping the sponge past the organ’s upper sphincter muscle.
The sponge emerges loaded with genetic material that holds the key to the
patient’s oesophageal health.
The sponge is then sent to a company that performs simple
genetic tests on the material to determine the patient’s risk for oesophageal
“Early detection is the whole ballgame when it comes to oesophageal
cancer,” Meltzer says. “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.”
With nearly half a million new cases a year, oesophageal
cancer is the eighth most-common cancer worldwide, with the highest rates in
parts of Africa and Asia.
The five-year survival rate for people with cancer confined
to the oesophagus is 43%. When it spreads to nearby tissues or organs, that
rate falls to 23%.
In previous research, Meltzer has performed rigorous testing
on the set of genetic biomarkers he uses to diagnose Barrett’s. The gene
combination of p16, NELL1, AKAP12 and TAC1 has yielded a sensitivity of nearly
92% percent and has offered reliable diagnoses.
Medicine has never had routine screening methods for the
disease. Both endoscopy and biopsy are less-than-ideal, since they’re inexact,
expensive and rely on random tissue samples, rather than material from the
whole oesophagus lining.
“It’s actually possible to miss early cancerous cells using
endoscopy with biopsy and most patients with Barrett’s don’t ever undergo
endoscopy,” says Meltzer. “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.”
Meltzer administered the EsophaCap test to 94 people over
the course of the study. Eighty-five percent of subjects were able to swallow
the capsule, with 100% successful sponge retrieval. Endoscopic evaluation of
the patients after EsophaCap administration, Meltzer reported, showed no
evidence of bleeding, pain, trauma or other adverse reactions to the test.
Reference: Meltzer SJ, et al. Methylation Biomarker Panel
Performance in EsophaCap Cytology Samples for Diagnosing Barrett’s Esophagus: A
Prospective Validation Study. Clinical Cancer Research .Published Online First 22