Scientists have developed an endoscope that uses near-infrared light to spot early warning signs of oesophageal cancer, according to research published in the Journal of Biomedical Optics.

Researchers at the Cancer Research UK Cambridge Institute sprayed a dye on oesophageal tissue samples taken from people with Barrett’s oesophagus – a condition that increases the risk of developing oesophageal cancer. The dye sticks to healthy oesophageal cells but not to pre-cancerous cells. They then shone near-infrared light on the tissue, which is just beyond the red colours that our eyes can normally see, and used a special camera to detect the near-infrared light the dye gave out.

Researchers had tried this approach before but had used a dye that gave out visible light to spot pre-cancerous cells. Problems arose because when cells are exposed to visible light, they naturally emit visible light themselves, making the distinction between healthy and abnormal cells hard to see.

But, by using a dye that gives out near-infrared light, scientists refined the process so they could make the distinction.

This new technique could be used to monitor people with Barrett’s oesophagus who have an increased risk of developing oesophageal cancer, and spot early signs that cancer might be developing before the person has any symptoms.