February 13, 2009--A team of researchers from Northwestern University and NorthShore University HealthSystem (formerly Evanston Northwestern Healthcare) in Chicago, IL have developed a way to examine cell biopsies and detect never-before-seen signs of early-stage pancreatic cancer, according to a new paper in the Optical Society (OSA) journal Optics Letters.
Though the new technique, called partial wave microscopic spectroscopy, has not yet proven effective in double-blind clinical trials, it may one day help diagnose cancers of the pancreas and, potentially, other organs at their earliest and most treatable stages, before they spread.
Pancreatic cancer is typically diagnosed by hospital pathologists who look for telltale changes to the morphology of pancreatic cells when they examine cell biopsies under the microscope. The problem is that in the early stages of cancer, many early-stage cancer cells appear normal. By the time the cancerous cells undergo observable changes, it may be too late in the disease progression for effective treatment. In fact, only 7% 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 it has already metastasized.
"In the beginning, cells look normal," says Vadim Backman, a professor of biomedical engineering at Northwestern University who developed partial wave microscopic spectroscopy with his former graduate students Yang Liu and Hariharan Subramanian and postdoctoral fellow Prabhakar Pradhan. The new technique measures nanoscopic changes to the interior architecture of cells--changes that may signal signs of cancer even in cells that look normal under the microscope. The new technique works by detecting fluctuations in the cells' refractive index. The Chicago researchers showed that by quantifying these fluctuations, partial wave spectroscopy could identify cancer cells even in cases where they had not been detected by pathologists.
Partial wave microscopic spectroscopy may be a boon to medicine, if it proves effective in clinical trials at detecting cancers early--especially for people with pancreatic cancer, which is one of the most deadly forms of cancer. According to the National Cancer Institute, more than 37,000 men and women in the U.S. alone were diagnosed with pancreatic cancer in 2008, and statistically 95% of them will succumb to the disease within five years.
For more information, see "Partial wave microscopic spectroscopy detects sub-wavelength refractive index fluctuations: an application to cancer diagnosis," Hariharan Subramanian et al., Optics Letters, Vol. 34, No. 4, Feb. 15, 2009.
--Posted by Gail Overton, [email protected].