From Our 2007 Archives
Test Brings Early Pancreatic Cancer to Light
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WEDNESDAY, Aug. 1 (HealthDay News) -- A light-based test that doesn't focus on the pancreas itself may be the first safe means of accurately spotting early pancreatic cancer in people at high risk for the lethal illness, researchers say.
The screening requires a routine endoscopic biopsy of the duodenum, the upper part of the small intestine. When an early-stage pancreatic cancer is present, cells in the duodenum give off different light-scattering effects than if the disease is not there, U.S. researchers explain in the Aug. 1 issue of Clinical Cancer Research.
In the small pilot study of 51 patients, the optical screen was 100 percent effective in spotting patients with surgically removable pancreatic tumors.
"This is potentially a way of prescreening [high-risk] patients," said lead researcher Vadim Backman, a professor of biomedical engineering at Northwestern University's McCormick School of Engineering and Applied Sciences, in Evanston, Ill.
He explained that patients with a family history of pancreatic cancer now "live their whole life thinking, 'What is going to happen to me?'"
He added that the new test raises "a possibility of taking these patients and screening them on an annual basis without risk."
The test, which has already proven useful in detecting early-stage colon cancer using rectal tissue, does need to be validated in a larger, prospective trial, experts said.
However, if that works out, "it would be a very important tool for our patient community, as well as the doctors that treat them," said Julie Fleshman, president and CEO of the nation's largest nonprofit pancreatic cancer advocacy group, the Pancreatic Cancer Action Network (PanCAN).
"We look at this with hopeful optimism," she added. "The study was done in a small number of patients, however, so more research needs to be done."
Any advance would be welcome against pancreatic cancer, the fourth leading cancer killer in the United States. According to the American Cancer Society, more than 33,000 Americans die annually from the disease, which is especially lethal because it typically shows no symptoms until it has already spread to other organs.
Opera superstar Luciano Pavarotti is perhaps the most high-profile patient currently battling the illness, which has few effective treatments.
"The survival rate is extremely low, lower than any other type of cancer -- below 5 percent over five years, and a third of patients die within one year of diagnosis," Backman said.
The scanning technologies that can detect other tumors can't pick up early-stage pancreatic cancer, he noted, and invasive tests that biopsy or probe the pancreas come with a more than 20 percent risk of serious complications. "It's an extremely difficult organ to work with," the researcher said.
However, the Northwestern team had already tested its light-based technology in colon cancer. The researchers found that it could pick up traces of early malignancy using biopsies taken from a separate but adjacent site, the rectum.
"So, we asked the question, 'Can we find out if a patient has pancreatic cancer or not without actually going inside the pancreas?' " Backman explained.
They honed in on the duodenum, a portion of the small intestine that lies very near the pancreas, but is much more accessible to biopsy. In a study of the 51 patients -- some of whom had various stages of pancreatic cancer -- the scientists used standard upper endoscopy to retrieve a tiny biopsy of duodenal tissue.
Then they subjected cells from these tissues to two light-scattering tests designed to detect aberrations that signal a nearby pancreatic malignancy.
The results were impressive, with the researchers achieving 100 percent accuracy in spotting both early- and later-stage pancreatic tumors.
A few false-positives were also reported, the team noted. It's not clear whether these results were simply wrong, or if they suggested that those patients were at high risk of developing pancreatic cancer in the future and needed to be monitored closely.
Both Backman and Fleshman stressed that such a test would probably only be used as routine screening on patients with a family history of pancreatic disease. "We do know that about 10 percent of cases are genetic," Fleshman pointed out.
A pancreatic cancer test aimed at the wider population -- similar to the way women get regular mammograms or men go for PSA prostate cancer blood tests -- is still a long way off, she said.
"I hope someday that we do have something that is part of a regular physical for a disease like this," Fleshman said. "But I don't think that that is on the near horizon."
In the meantime, Backman's team is already engaged in a larger trial involving more than 200 patients. That trial will examine how good the optical tests are at differentiating between pancreatic cancer and other, benign conditions that can affect the organ, such as pancreatitis or cysts.
"We will also compare patients with a family history against those who don't have a family history," he said.
Fleshman said her group is excited by the test's potential, but much more work needs to be done.
"This continues to illustrate the need for more research dollars into this disease," she said. "Because, even if we found an early detection method, we still need much better treatment options for patents."
SOURCES: Vadim Backman, Ph.D., professor, biomedical engineering, McCormick School of Engineering and Applied Science, Northwestern University, Evanston, Ill.; Julie Fleshman, president and CEO, Pancreatic Cancer Action Network, El Segundo, Calif; Aug. 1, 2007, Clinical Cancer Research
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