Using a tiny specialized microscope that can see living cells inside patients in real time, physicians at Yale-New Haven Hospital are developing new methods to diagnose pancreatic cancer at an early, more survivable stage.
The new tool is a very small confocal laser microscope that fits at the end of a long, thin, flexible tube.
The instrument is then threaded through the complex anatomy of the pancreas, bile ducts and other related tissues.
One image from the confocal microscope is worth 1,000 biopsies, said Dr. Priya Jamidar, director of endoscopy at Yale-New Haven. (He is pictured with a model of the pancreas, small intestine, and surrounding blood vessels.)
The microscope yields images that usually can only be obtained from a pathology lab. The difference is that results are immediate.
Using a tube about an eighth of an inch wide, the microscope can resolve objects about 50 microns wide, which is half the diameter of a single hair.
Identifying and removing pancreatic cancer early is essential to a favorable outcome, Jamidar said.
The pancreas produces insulin, other hormones, and digestive enzymes.
The American Cancer Society estimates that about 34,000 Americans a year are likely to develop cancer of the pancreas. Approximately 32,000 men and women succumb to the disease annually in the U.S.
That makes pancreatic cancer the 10th cancer in incidence and the fourth in death.
Survival rates are low because pancreatic cancer is generally only found after it has started to spread, Jamidar said. The cancer produces few, if any early symptoms.
Pancreatic cancer has a “terrible prognosis because we pick it up late,” he said. Only about 1 to 2 percent of patients are alive five years after the diagnosis, Jamidar said.
While it is relatively straight forward to inspect the esophagus or large colon with an endoscope, navigating the tube through the stomach and into the ducts in the pancreas is more complicated.
“With the colon and esophagus you can diagnose disease immediately,” Jamidar said.
Finding abnormal growth in the narrow twisting ducts inside the pancreas is difficult.
Cancer usually forms at the “head” of the pancreas, which is nestled against the small intestine, beneath and behind the stomach.
If suspicious cells are spotted, the physician then must obtain a biopsy sample. A pancreatic biopsy is only about 50 percent accurate, Jamidar said. If not removed promptly, cancer in the pancreas may spread to the intestine, liver and lungs.
The endoscopic confocal laser microscope can resolve groups of cells in the walls of the pancreas.
“One woman had stricture in the bile duct. We took biopsies and one was suspicious. When we looked with the confocal microscope it was highly suspicious,” Jamidar said.
The typical confocal microscope used in endoscopy is about 3 millimeters in diameter, roughly the thickness of three nickels pressed together.
A normal pancreatic duct is about four to six millimeters wide. An early stage cancer is around 10 millimeters in diameter, less than one third of an inch.
“That’s why we need the instrument to be so small,” Jamidar said.
The confocal microscope used at Yale-New Haven is produced by Cellvizio Inc., of Newtown Pa., uses a laser, fluorescent dye and complex optics.
Basically, the microscope detects fluorescent light triggered by a laser. A filter removes the laser light, allowing the fluorescent light to pass through a very small aperture. The light then hits a photodetector that converts the image into electronic signals.
The data then goes to a computer that displays the image on a screen.
Jamidar and colleagues continue to learn how to interpret the images.
Jamidar said he hopes to publish an article on the initial results of the microscope.
“It’s really cutting edge. It’s early on, but I’m convinced we’ll get there,” he said.