To test the effectiveness of the technology in screening for pancreatic cancer, Backman and Liu have been collaborating with Randall E. Brand, M.D., a gastroenterologist with Evanston Northwestern Healthcare who specializes in pancreatic cancer and is an associate professor of medicine at Northwestern’s Feinberg School of Medicine. They have shown that they can detect changes in the duodenal tissue and that these optical markers predict the presence of cancer.
The researchers found that the same optical markers that were significant in earlier colon cancer studies at ENH using Backman’s technology proved also to be significant for pancreatic cancer. An optical marker is a signature at the sub-micro level that shows changes in tissue due to the presence of a precancerous lesion or cancer.
“We also found that the diagnostic performance of the technique is not compromised by risk factors in the patients,” said Liu, now a senior scientist at Johnson & Johnson. “The markers don’t depend on age -- the cells know if they are old or if they are cancerous. The markers do not change if the patient is a smoker. And the markers do not change with the location, stage or size of the tumor in the pancreas.”
Most cancers in the pancreas originate from the main pancreatic duct, a 10-centimeter-long duct located in the pancreas that perforates the duodenum, the first and shortest part of the small intestine. The pancreatic duct is difficult to reach and if attempted, it is a risky procedure with a 20 percent chance of significant complications, including acute pancreatitis.
In the study, biopsies of normal-looking tissue were taken from the duodenum near the opening of the pancreatic duct for analysis. For each sample, light is shined on the tissue. The light scatters and some of it bounces back to sensors in the fiber-optic probe. A computer analyzes the pattern of light scattering, looking for the “fingerprint” of carcinogenesis in the nanoarchitecture of the cells.
The researchers found the technique identified with 100 percent accuracy each person who had a resectable cancerous tumor in the pancreas. (Resectable means the tumor can be removed surgically, which in this study is defined as stage 1 or 2 tumors.) Some people were identified who did not have a tumor; it is uncertain whether this is a false finding or if it means those people could be at risk for developing pancreatic cancer and need to be watched closely.
The method combines two complementary technologies developed by Backman and colleagues in his lab: four-dimensional elastic light-scattering fingerprinting (4D-ELF) and low-coherence enhanced backscattering spectroscopy (LEBS). The researchers found that the two combined work better than one alone in pancreatic cancer screening.
The success of the pancreatic cancer screening study follows on the heels of extremely positive results in studies using the two optical technologies for the early detection of colon cancer. In the colon cancer work, Backman has been collaborating with ENH gastroenterologist Hemant Roy, M.D., associate professor of medicine at the Feinberg School, who is overseeing clinical trials at Evanston Hospital. (Roy also is a collaborator on the pancreatic cancer work.)
“The results in our colon cancer work, in which measurements are taken from the rectum, led us to wonder if we could use tissue taken from the duodenum to screen for pancreatic cancer,” said Backman. “Our study published in Clinical Cancer Research has shown that not only can we detect large tumors but early tumors as well.”
“This new work extends the concept of the field effect, or field carcinogenesis, to the pancreas,” said Roy. “While the pancreatic cancer research is preliminary, this extraordinarily exciting work offers the prospect of providing an accurate and practical means for screening this lethal malignancy.”
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The pancreatic cancer screening test currently is in a larger clinical trial at Evanston Hospital to validate the effectiveness of the technique. Funded by the National Science Foundation (NSF) and the National Institutes of Health (NIH), the study has approximately 200 participants. The pilot study also was supported by NSF and NIH.
In addition to Backman, Yang (lead author), Brand and Roy, other authors on the CCR paper, titled “Optical markers in duodenal mucosa predict the presence of pancreatic cancer,” are Vladimir Turzhitsky and Young L. Kim, from Northwestern University’s department of biomedical engineering, and Nahla Hasabou, Charles Sturgis, Dhiren Shah and Curtis Hall, from Evanston Northwestern Healthcare’s department of internal medicine. |