Detecting cancer with a ‘pill on a string’

Some people who have long-term symptoms of heartburn or acid reflux develop a condition called Barrett’s oesophagus, areas of abnormal cells that may turn into cancer in a small number of people.

Early detection for this type of cancer is important. It requires a referral for an endoscopy, where a camera is fed through your mouth to your stomach, which can be uncomfortable for some people and is expensive for the health service.

The Cytosponge or known as ‘pill on a string’ (right) was created in Cambridge by Professor Rebecca Fitzgerald. The aim was to test whether it could successfully collect cells from the oesophagus and detect cancer.

The early stages of this trial was supported by the NIHR Cambridge CRF research nurses. Patients were invited to attend the NIHR Cambridge CRF and were asked to swallow a small capsule (about the size of a multivitamin pill) which is attached to a string. When it gets to the stomach the capsule disintegrates and releases a small sponge

The sponge is then pulled back using the string, collecting cells as it comes back up the oesophagus which can be sent off for testing.

After the early studies were completed in Cambridge, phase 3 of this study was rolled out to GP surgeries. The researchers studied 13,222 participants who were randomly allocated to being offered the sponge test or being looked after by the GP in the usual way.

Over the course of a year, the odds of detecting Barrett’s were ten times higher in those offered the Cytosponge with 140 cases diagnosed compared to 13 in usual care. In addition, the Cytosponge diagnosed five cases of early cancer (stage 1 and 2), whereas only one case of early cancer was detected in the usual care group.

With the success of the cytosponge, this means testing could take place in the community, identifying those who have suspected Barrett’s oesophagus faster and reducing the number of those who require an endoscopy. The cytosponge could revolutionise testing and save the NHS money.

You can read the latest press release on the results of the phase 3 trials.