Optical techniques show continued promise in detecting pancreatic cancer

WASHINGTON, March 2 (Chinese media) -- Optical technology developed by a Northwestern University professor of biomedical engineering has been shown to be effective in detecting the presence of pancreatic cancer through analysis of neighboring tissue in the duodenum, according to clinical trial results published on Monday in the journal Disease Markers.

The promising new technology -- which researchers hope could help raise the extremely low survival rate of pancreatic cancer patients by aiding early detection -- uses novel light-scattering techniques to analyze extremely subtle changes in the cells of the duodenum, part of the small intestine neighboring the pancreas. The cells are obtained through a minimally invasive endoscopy.

The study shows that cells that appear normal using traditional microscopy techniques do show signs of abnormality when examined using the Northwestern technique, which provides cell analysis on the much smaller nanoscale.

The technology was developed by Vadim Backman, professor of biomedical engineering at the McCormick School of Engineering and Applied Science at Northwestern, and Vladimir Turzhitsky, a graduate student in Backman's lab. Clinical trials have been conducted in collaboration with Hemant Roy, director of gastroenterology research at North Shore University Health System, and Randall Brand, a gastroenterologist at the University of Pittsburgh Medical Center.

In the study of 203 patients, the technique accurately discriminated with 95 percent sensitivity between healthy patients and those with differing stages of the disease. Only 5 percent of patients were found to have been diagnosed with false negatives after testing.

The specificity of the testing group was 71 percent. These results confirm those of an earlier study of 51 patients published in August 2007 in the journal Clinical Cancer Research.

The larger number of patients in the more recent study allowed researchers to calculate the "area under the receiver operator characteristic" (AUROC), which is an analysis of the accuracy of the test in distinguishing healthy samples from diseased samples.

While the sensitivity and specificity of tests may vary based on the threshold set by researchers for diagnosis, the AUROC measures the overall efficacy of the diagnostic technique. The analysis showed an 85 percent AUROC for the Northwestern method. Clinically sound tests typically have an AUROC greater than 70 percent.

The study published in Disease Markers also reports promising results in detecting mucinous cyst lesions, which are a precursor to cancer. If confirmed in further clinical trials, this approach may lead to a method for early diagnosis.

Pancreatic cancer is among the most deadly forms of cancer, with a five-year survival rate of just 5 percent. It is so deadly, in part, because early detection is difficult. There is a high risk of complications if the pancreas is examined directly, so routine inspections for at-risk patients usually are not an option.

In fact, only 7 percent of people with pancreatic cancer are diagnosed in the earliest stages of the disease, when the cancer is still confined to its primary site. More than half of all people with the disease are not diagnosed until the cancer has already metastasized.

"Typically, by the time a patient is diagnosed with pancreatic cancer, it is too late for the most successful treatments," says Backman. "Our hope is that this technology will provide a better method for early diagnosis of the disease, which could greatly improve the survival rate."