‘Pill-on-Thread’ Could Replace Half of Cancer Screenings

Cambridge researchers show capsule sponge test safely identifies esophageal cancer risk, potentially sparing 500,000 patients from invasive endoscopies annually.

A simple pill connected to a thread could replace uncomfortable endoscopies for more than half of patients being monitored for esophageal cancer risk, according to a major study from the University of Cambridge published today in The Lancet.

The “capsule sponge” test correctly identified over 54% of Barrett’s esophagus patients as low-risk, with only 0.4% developing high-grade precancerous changes that required treatment. This rate falls well below the 3% clinical threshold used to justify invasive procedures, suggesting these patients could safely skip regular endoscopies.

A Gentler Alternative to Camera Down the Throat

Esophageal cancer remains one of medicine’s toughest challenges. Fewer than one in five patients survive five years after diagnosis—a statistic that hasn’t improved in three decades. Meanwhile, cases have quadrupled since the 1970s.

Patients with Barrett’s esophagus, a condition where stomach acid changes the lining of the food pipe, face a one-in-ten chance of developing cancer. Those with more severe cell changes called high-grade dysplasia see their risk double to one in five.

Currently, these patients undergo regular endoscopies—often 10 or more over their lifetime. The procedure involves threading a camera down into the stomach, requires sedation, and patients need someone to drive them home afterward.

“The chances of Barrett’s progressing to cancer are low, and endoscopies are not very pleasant procedures,” explained Professor Rebecca Fitzgerald, Director of the Early Cancer Institute at Cambridge. “What we need is an alternative surveillance method that’s less invasive, easier to administer and more reliable.”

How the Pill-on-Thread Works

The capsule sponge involves swallowing a pill connected to a thin thread. Once in the stomach, the pill dissolves to release a small sponge. When pulled back up through the esophagus, it gently collects cell samples.

Laboratory technicians then examine these cells under a microscope, looking for two key warning signs: abnormalities in the p53 protein that normally prevents tumors, and cells that appear irregular or misshapen.

The Cambridge team tested this approach in 910 patients across 13 UK hospitals. Results showed remarkable precision in risk assessment:

• 15% classified as high-risk had a 38% chance of precancerous changes
• 31% deemed moderate-risk required continued endoscopy monitoring
• 54% identified as low-risk had only 0.4% chance of dangerous cell changes
• Patients with both warning signs faced an 85% likelihood of precancerous changes

Real-World Impact

Duncan Cook, a 57-year-old plumbing engineer from Cambridge who participated in the study, welcomed the results after nearly 20 years of regular endoscopies.

“I have a busy job and being able to have the sponge instead of an endoscopy would be much easier and save a lot of time,” Cook noted. “The sponge test is faster, you don’t need sedation for it, and you don’t need to find someone to come with you to drive you home after. I was able to have the test done and go right back to work after.”

The test can be administered by nurses in GP practices rather than requiring specialist hospital facilities. This could dramatically reduce NHS resource strain while maintaining patient safety.

Professor Peter Sasieni from Queen Mary University of London emphasized the safety implications: “Given that the risk of these individuals progressing to dysplasia and then to oesophageal cancer is so low, it should be safe to replace their usual endoscopy with the capsule sponge.”

Looking Ahead

The research team also tested an artificial intelligence system that could reduce pathologist workload by two-thirds without missing any positive cases. This digital approach correctly identified all patients with dangerous cell changes while eliminating the need to review 68% of samples.

Cancer Research UK Chief Executive Michelle Mitchell called the technology “one of the most promising breakthroughs in early detection we have seen to date,” noting its potential to “spare significant numbers of people from discomfort and invasive endoscopies.”

The study found that relying on segment length alone—a proposed alternative approach—would have missed three esophageal cancers, highlighting the superior accuracy of the biomarker-based capsule test.

With over 500,000 people in the UK living with Barrett’s esophagus, widespread adoption could transform cancer surveillance while freeing up endoscopy resources for higher-risk patients who need immediate attention.