What if swallowing a pill with a camera could detect the earliest signs of cancer? The tiny camera is designed to take high-quality, color pictures in confined spaces. Such a device could find warning signs of esophageal cancer, the fastest growing cancer in the United States.
In the past 30 years diagnoses of esophageal cancer have more than tripled. The esophagus is the section of digestive tract that moves food from the throat down to the stomach. Esophageal cancer often follows a condition called Barrett's esophagus, a noticeable change in the esophageal lining. Patients with Barrett's esophagus can be healed, avoiding the deadly esophageal cancer. But because internal scans are expensive most people don't find out they have the condition until it's progressed to cancer, and by that stage the survival rate is less than 15 percent.
An endoscope is a flexible camera that travels into the body's cavities to directly investigate the digestive tract, colon or throat
These tools are long, flexible cords about 9 mm wide, about the width of a human fingernail. Because the cord is so wide patients must be sedated during the scan.
A wireless scope manufactured by a different group, originally designed to pass through the body and detect intestinal cancer, is now being marketed for esophageal cancer screening. The competing technology comes in a pill about the width of an adult fingernail and twice as long. By contrast, the UW's scanning fiber endoscope's dimensions are about half as big and the device fits inside a standard pill capsule. The pill could be even smaller, Seibel said, but the researchers chose a size that would be easy to handle and swallow.
Another disadvantage of wireless capsules is they only allow a single fly-by view."You have no control over the other pill once it's swallowed. It just flutters down," Seibel said. But since the UW scope is tethered, the doctor can move it up and down along the region of interest.
Only a small percentage of people who get Barrett's esophagus, about 5 percent to 10 percent, develop cancer. So any screening method must have a low price to be cost-effective.
The research was funded by the National Cancer Institute and Pentax Corp. Early funding was provided by the Whitaker Foundation and the Washington Technology Center. Co-authors at the UW are Drs. Michael Kimmey and Jason Dominitz in gastroenterology at the UW Medical Center; Richard Johnston, C. David Melville and Cameron Lee in mechanical engineering; Steve Seitz in computer science and engineering; and Robert Carroll, now in electrical engineering and computer science at the University of California, Berkeley.