Endoscopy Detects Pancreatic Cancer

A routine examination called endoscopy can detect pancreatic cancer — the deadly form of cancer that killed Patrick Swayze — with 100 percent accuracy, according to doctors at Mayo Clinic's Florida campus. The minimally invasive technique, called Polarization Gating Spectroscopy, may be able to detect the disease at an early stage, vastly increasing the chances of survival. Pancreatic cancer is one of the deadliest cancers and will strike almost 43,000 people in 2012, according to estimates by the American Cancer Society. Since the pancreas is located deep inside the body and can't be felt by doctors during routine exams, it usually isn't diagnosed until it's advanced, and prognosis is grim. It is only curable in 5 percent of cases, and even when it is surgically removed, 70 percent of patients have a recurrence that is fatal, according to Mayo researchers. Currently, there is no method to detect the cancer early enough to cure a substantial number of patients, says Dr. Michael Wallace, the chairman of the Division of Gastroenterology at Mayo Clinic in Florida. It's usually detected through an imaging scan, followed by an invasive biopsy. Tumors found in this way are usually advanced. The Mayo researchers theorized that there may be changes in the nearby tissue of the small intestine which is much more accessible than the pancreas itself. With the new technique, a light is attached to a probe which measures changes in the cells and blood vessels in tissue that appears normal in the small intestine that are produced by a growing cancer in the adjoining pancreas. Since a growing cancer needs extra blood, normal tissue in the area of the tumor shows evidence of enlarged blood vessels and changes in the amount of oxygen in the blood. Other studies have found that the "field effect" can be measured as far away as 11 inches from the tumor itself. The probe acts “a bit like a metal detector that beeps faster and louder as you get close to cancer,” Wallace says. The researchers are measuring within six to 10 inches of the pancreas in the small intestine immediately next to the pancreas. Dr. Wallace and his team tested the probe on 10 patients who were later determined to have pancreatic cancer, and on nine participants who did not have pancreatic cancer. By measuring the diameter of blood vessels close to the pancreas and the amount of oxygen in the blood, they detected all 10 cancers. But when healthy volunteers were tested, the probe was only 63 percent accurate in determining whether or not the person had pancreatic cancer. "There is room for improvement in this instrument, and our group is working on that," Dr. Wallace says. "If the studies confirm the early results, it would make the pancreas accessible to a much simpler upper endoscope, and that would be a real advance in the treatment of pancreatic cancer. "No one ever thought you could detect pancreatic cancer in an area that is somewhat remote from the pancreas, but this study suggests it may be possible," he says. "Although results are still preliminary, the concept of detection field effects of nearby cancers holds great promise for possible early detection of pancreatic cancer," says Dr. Wallace.