Light-based probe 'sees' early cancers in first tests on human tissue

In its first laboratory tests on human tissue, a light-based probe built by researchers at Duke University's Pratt School of Engineering almost instantly detected the earliest signs of cancer in cells that line internal organs.

If the preliminary success of the "optical biopsy" is confirmed through clinical trials, such a device could ultimately provide a particular advantage for early diagnosis, treatment and prevention of many types of cancer, according to the researchers. The vast majority of cancers start in the body's epithelial cells, which line the mucous membranes in the lungs, esophagus and gut.

"About 85 percent of all cancers start in the epithelium. It may be, for example, brain cancer that causes a patient's death, but that cancer might have originated in the colon or other site of epithelial tissue," said Adam Wax, professor of biomedical engineering. "Being able to detect pre-cancer in epithelial tissues would therefore help prevent all types of cancer by catching it early, before it has a chance to develop further or spread."

In some instances, the technique, known as "fa/LCI" (frequency-domain angle-resolved low coherence interferometry), might ultimately enable doctors and their patients to avoid removal of tissue for biopsy, Wax said. In other instances, he added, fa/LCI could help physicians pinpoint suspicious cells during a traditional biopsy procedure, making it less likely for a cancerous lesion to escape detection.

Wax and his former graduate student John Pyhtila reported in the March 2007 issue of Gastrointestinal Endoscopy that their fiber-optic device reliably differentiated between healthy and precancerous digestive tissue taken from the stomach and esophagus of three patients known to have a precancerous form of a condition called Barrett's esophagus. In less than a second, their fa/LCI-enhanced version of an endoscope, instruments used to visualize internal organs, provided the clinical information required for diagnosis.

The work was supported by the National Cancer Institute and the National Science Foundation.

"Our initial study is very promising," Wax said of the findings. "We looked at tissue removed from just a handful of patients and were able to get 100 percent sensitivity. We could detect pre-cancer in the esophagus and distinguish it from normal tissue like you would find in the stomach."

The fa/LCI device detects irregularities in the nucleus, or central component, of cells, through changes in the way laser light scatters. "The size and shape of cell nuclei are powerful indicators of this precancerous condition called dysplasia, which literally means 'bad growth'," Wax said. "Typically, nuclei are a fairly consistent size. However, when you go down the road toward cancer, you get irregular and enlarged cell nuclei.

"Our device lets us measure those changes with much better accuracy than any imaging technique," Wax said.

His team plans to begin a small clinical trial of the advanced endoscope in collaboration with researchers at Duke University Medical Center. The team also is conducting animal studies to test the feasibility of incorporating fa/LCI into instruments for examining the colon, lung and other organs. Based on a study in hamsters, Wax and Duke postdoctoral researcher Kevin Chalut reported in the February 2007 issue of Cancer Epidemiology Biomarkers & Prevention that the technique might also be used in the identification of early lung cancer.

Wax said he and his colleagues have launched a company, called Oncoscope, to pursue the commercial development of fa/LCI devices. If all goes well, a new and improved endoscope might be ready for the clinic in three to five years, he said.

Source: Duke University

Related stories:

Ultrathin films promise a multitude of uses
Imagine a special coating that can be applied to any of a number of surfaces. With its application, carpets, furniture and clothing become super-resistant to stains; automobile bodies are impermeable to water and rust; stents put in place during heart surgery no longer are susceptible to tissue growth that can restrict blood flow; and cell cultures are more easily produced in the laboratory.
Scientists discover new link in pathway to cancer: hope for drug design
(PhysOrg.com) -- University of Manchester scientists have identified an exciting connection between a cell’s extracellular environment and the activity of a signalling pathway molecule that controls the development of organs and tissues, as well as cancer and kidney disease.
Black raspberries slow cancer by altering hundreds of genes
New research strongly suggests that a mix of preventative agents, such as those found in concentrated black raspberries, may more effectively inhibit cancer development than single agents aimed at shutting down a particular gene.
Low cholesterol associated with cancer in diabetics
Low levels of LDL cholesterol as well as high levels are associated with cancer in patients with type 2 diabetes, found a prospective cohort study published in CMAJ.
Gene that causes childhood cancer neuroblastoma is found
Scientists have discovered gene mutations that are the main cause of the inherited version of the childhood cancer neuroblastoma. In addition, the researchers found that the same mutations play a significant role in high-risk forms of non-inherited neuroblastoma, the more common form of the disease.
Yale undergrads' Amazon trip yields a treasure trove of diversity
A group of Yale undergraduates have discovered dozens of potentially beneficial bioactive microorganisms within plants they collected in the Amazon rain forest, including several so genetically distinct that they may be the first members of new taxonomical genera.
Dense tissue promotes aggressive cancers
New research may explain why breast cancer tends to be more aggressive in women with denser breast tissue. Breast cancer cells grown in dense, rigid surroundings step up their invasive activities, Vanderbilt-Ingram Cancer Center investigators report in the Sept. 9 issue of Current Biology.

Face transplant patient can smile, blink again
(AP) -- Transplanting faces may seem like science fiction, but doctors say the experimental surgeries could one day become routine. Two of the world's three teams that have done partial face transplants reported Friday that their techniques were surprisingly effective, though complications exist and more work is still needed.

News discussion:

Medicine & Health news