Shedding light on esophageal cancer.

• Position: Diagnosis

A tiny light source and sensors attached to an endoscope may provide a more accurate way to identify pre-cancerous cells in the lining of the esophagus. Developed by biomedical engineers at Duke University, Durham, N.C., and tested successfully on patients during a clinical trial at the University of North Carolina, Chapel Hill, the device holds the promise of being a less invasive method for testing those suspected of having Barrett's esophagus, a change in the lining of the esophagus due to acid reflux.

Acid reflux occurs when stomach acid splashes, or refluxes, up into the esophagus. Long periods of acid reflux can change the cells that line the esophagus, making them appear more like intestinal ceils than esophageal ones. These cellular changes can be a precursor to cancer. As in most cancers, early indication often leads to better outcomes for patients. Barrett's esophagus afflicts more than one percent of the U.S. population, with most patients above the age of 50.

Using an endoscope to reach the esophagus via the nose, physicians shine short bursts of light at locations of suspected disease and sensors capture and analyze the light as it is reflected back. In particular, doctors are trying to spot characteristic changes within the layer of cells known as the epithelium, which lines 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 spot the telltale signs of cells that are changing...