Light technology could aid oesophageal cancer detection

Developed by biomedical engineers at Duke University and successfully tested on patients during a clinical trial at the University of North Carolina at Chapel Hill, the device holds the promise of being a less invasive method for testing patients suspected of having Barrett’s esophagus − a change in the lining of the esophagus due to acid reflux.

Long periods of acid reflux can change the cells that line the esophagus, making them appear more like intestinal cells than esophageal cells. These cellular changes can also be a precursor to cancer. As in most cancers, early identification of these pre-cancerous cells often leads to better outcomes for patients.

Using an endoscope to reach the esophagus via the nose, physicians shine short bursts of light at locations of suspected disease, after which sensors capture and analyse the light as it is reflected back. In particular, they are trying to spot characteristic changes within the layer of cells known as the epithelium, which line cavities and surfaces throughout the body.

’By interpreting the way the light scatters after we shine it at a location on the tissue surface, we can the spot the tell-tale signs of cells that are changing from their healthy, normal state to those that may become cancerous,’ said Neil Terry, a PhD student working in the laboratory of Adam Wax, an associate professor of biomedical engineering at Duke’s Pratt School of Engineering, who developed the device.

’Specifically, the nuclei of pre-cancerous cells are larger than typical cell nuclei and the light scatters back from them in a characteristic manner,’ Terry continued. ’When we compared the findings from our system with an actual review by pathologists, we found they correlated in 86 per cent of the samples.’

The technology that Wax and his team developed for cancer detection is known as angle-resolved low-coherence interferometry (a/LCI). The technique is able to separate the unique patterns of the nucleus from the other parts of the cell and provide representations of its changes in shape in real time.

’This optical approach of sampling allows us to cover more tissue sites in less time and has the potential to significantly improve our ability to spot and monitor these pre-cancerous cells,’ Wax said. ’This type of approach could be used to improve and perhaps one day supplant the physical biopsies currently being used.’

Wax pointed out that, since approximately 85 per cent of all cancers begin within the layers of the epithelium in various parts of the body, the new system could also work in such cancers as those of the colon, trachea, cervix or bladder.