Capsule Sponge Test Could Replace Endoscopies for Monitoring Esophageal Cancer Risk

Esophageal cancer remains a challenging disease to treat, with fewer than 20% of patients surviving beyond five years of diagnosis—a statistic that has remained largely unchanged for decades. One of the precursors to this cancer is Barrett’s esophagus, a condition in which the cells lining the food pipe undergo abnormal changes. While progression from Barrett’s esophagus to cancer is relatively rare, patients require frequent, invasive endoscopies to monitor for pre-cancerous changes. These procedures are resource-intensive and uncomfortable. Now, a new study has found that a capsule sponge test could serve as a less invasive alternative for monitoring over half of these patients, potentially reducing the need for endoscopy.

The study was led by researchers at the University of Cambridge (Cambridge, UK) and collaborators from 13 hospitals across the UK. Their research focused on adapting the capsule sponge test—previously used to diagnose Barrett’s esophagus—for stratified patient monitoring, aiming to identify those at high risk of progression to cancer and reduce unnecessary procedures in low-risk individuals. The capsule sponge test involves swallowing a pill attached to a string. Once the capsule reaches the stomach, it dissolves and releases a sponge that, when pulled back up, collects cells from the lining of the esophagus. These cells are then stained and examined under a microscope. Pathologists look for two key markers: abnormalities in the tumor-suppressing protein p53 and the presence of atypical, irregular cells. These markers help classify patients according to their cancer risk.

Image: Capsule sponge opened to reveal the sponge (Photo courtesy of StillVision)

To assess the effectiveness of this approach for monitoring Barrett’s esophagus, the team enrolled 910 previously diagnosed patients from multiple UK hospitals. Each patient underwent the capsule sponge test and a traditional endoscopy. Based on the test results, patients were divided into three risk groups. About 15% were classified as high risk due to abnormal p53 and/or atypia; 38% of these had confirmed pre-cancerous changes, and the risk rose to 85% for those showing both markers. Patients with neither marker but who had other risk factors, such as longer Barrett’s segments or specific age and sex criteria, were placed in a moderate-risk group.

More than half—54%—were classified as low risk, showing neither biomarker nor other elevated risk factors. In this low-risk group, just 0.4% were later found to have high-grade dysplasia, and no cases of cancer were detected. The findings suggest that the capsule sponge test could significantly reduce the burden of endoscopies by reliably identifying patients at low risk of progression to cancer. For this group, invasive procedures may no longer be necessary. Meanwhile, high-risk patients can be prioritized for timely follow-up and potential treatment. As the capsule sponge can be administered by nurses in GP settings, it offers a cost-effective and more comfortable alternative to hospital-based endoscopy, making cancer surveillance more accessible and less disruptive for patients.

“Our findings suggest that the capsule sponge could help stratify patients with Barrett’s esophagus by risk and that half of them will fall into the low-risk group,” said Professor Peter Sasieni from the Cancer Research UK Cancer Prevention Trials Unit, Queen Mary University of London. “Given that the risk of these individuals progressing to dysplasia and then to esophageal cancer is so low, it should be safe to replace their usual endoscopy with the capsule sponge.”  

Related Links: 
Early Cancer Institute at the University of Cambridge
CRUK Cancer Prevention Trials Unit at Queen Mary University of London