Electronic nose helps detect oesophageal cancer and Barrett's oesophagus

A new portable electronic nose - also known as e-nose - appears to be able to accurately detect precursors of oesophageal cancer. In time, the e-nose may be employable to detect the precursor of oesophageal cancer - Barrett oesophagus - in general practice.

Oesophageal cancer and Barrett oesophagus is diagnosed late and at an advanced stage. This complicates treatment. The diagnosis of Barrett oesophagus is therefore important. This is a preliminary stage of oesophageal cancer in which white-coloured cells at the bottom of the oesophagus have been replaced by abnormal pink cells.

Diagnosing Barrett oesophagus currently takes place via an endoscope with a camera, which enters the oesophagus. This is not only a tedious procedure for the patient, but also costly. This makes the method unsuitable for population screening.

At the same time, the number of cases of oesophageal cancer and Barrett oesophagus has increased dramatically in recent decades. This makes it important to find a less expensive and burdensome method of diagnosis. Researchers at Radboudumc, Bernhoven and CWZ therefore investigated a portable electronic nose.

An e-nose is a device that measures volatile organic compounds (VOC) in exhaled air. These gaseous compounds are formed during a variety of metabolic processes in the human body. Changes in metabolism theoretically also lead to a different mix of those compounds. This makes it possible to measure inflammation and abnormal activity in cells in the breath, among other things.

Researchers investigated whether an e-nose is capable of reaching Barrett oesophagus. 400 patients participated in the study of which 129 had Barrett oesophagus and 141 had reflux, in which stomach acid flows back into the oesophagus. The control group consisted of 132 patients.

Yonne Peters, gastrointestinal liver researcher at Radboudumc: "After analysis, we saw clearly different exhalation profiles for these three groups. The sensitivity to pick up Barrett oesophagus was high, at 91 per cent. That means the test detected 91 out of 100 people with Barrett oesophagus based on the exhalation profile. Selection of people who do not have Barrett oesophagus - the specificity - is at 74 per cent."

"These are figures comparable for breast cancer and colon cancer screening," says MDL physician and coordinator of the study Peter Siersema. "After these encouraging figures, further research in larger groups of people is obvious. If these results hold up, partly because of its user-friendliness and low cost, this breathalyzer may become interesting for non-invasive screening of Barrett oesophagus in general practice."

That an e-Nose makes it possible to detect bacteria has long been clear. The Zutphen company eNose, for instance, has been working on the Aenose for some time. This intelligent electronic nose can detect the stomach bacteria Helicobacter pylori (H. pylori) in exhaled air. This bacterium can lead to stomach cancer.

This is possible thanks to the use of artificial intelligence, which looks for indicators of bacteria in the exhaled air. In doing so, the AI algorithm looks specifically at the breathing profile of patients, which differs in the presence of the bacteria.

AMC Amsterdam already developed an e-nose several years ago to diagnose what lung disease a patient has directly in the GP's consulting room. This makes it possible to make the right diagnosis faster and start treatment sooner.

Author: Wouter Hoeffnagel