Sponge-on-a-string Offers Screening Alternative

A quick, noninvasive sponge test accurately identified nearly 100% of low-risk Barrett esophagus patients without precancerous cells.

by Thomas Celona
December 11, 2025

Sponge-on-a-string Offers Screening Alternative

With the sponge-on-a-string screening method, a health care provider uses a plastic tool to place a pill at the back of a patient’s tongue. That pill is attached to a string, which is also connected to the tool. After the patient swallows the pill, stomach acid dissolves the pill to release a small sponge. Photo courtesy of Rebecca Fitzgerald

PEOPLE WITH BARRETT ESOPHAGUS, a condition where abnormal cells form after stomach acid damages the lining of the lower esophagus over time, have increased risk for esophageal cancer.

But regular screening with an endoscopy, which uses a tube with a light and a camera to examine the lining of the esophagus, can help to detect abnormal cells before they develop into cancer. However, this outpatient procedure requires patients to fast for about eight hours beforehand and be sedated. “We need a better way of being able to test people,” says Rebecca Fitzgerald, a gastroenterologist at Addenbrooke’s Hospital and the director of the Early Cancer Institute at the University of Cambridge in the U.K.

Fitzgerald helped develop a new tool that could make screening as simple as swallowing a pill. With this test, a patient swallows a capsule attached to a string. Stomach acid dissolves the capsule to release a small sponge. A doctor or nurse uses the string to pull the sponge up the patient’s throat. This collects millions of esophageal cells that a pathologist then analyzes for signs of cancer. Patients still must fast beforehand but typically only for four hours, and they do not need to receive anesthesia. The screening takes less than 10 minutes and can be done in a doctor’s office or pharmacy. “It’s very easy and convenient,” Fitzgerald says.

In a study published June 23, 2025, in the Lancet, 910 people who were diagnosed with Barrett esophagus in the U.K. underwent both the sponge test and an endoscopy. The sponge test indicated 489 people had a low risk of developing esophageal cancer. In subsequent endoscopies, Fitzgerald and colleagues confirmed 99.6% of these people had no precancerous cells, and 100% of them had no cancerous cells.

The findings suggest the sponge test could be used instead of an endoscopy for regular screening in people with Barrett esophagus at low risk for developing cancer, according to Fitzgerald. Additional studies are evaluating use of this tool in clinical care, but some U.K. clinics already use it. Fitzgerald says she expects other health care providers will soon follow suit.