A team led by a Northwestern University biomedical engineer has found that combining novel optical technologies with a common colon cancer screening test may allow doctors to more accurately detect the presence of colon cancer, particularly in women.
The study, led by Vadim Backman, professor of biomedical engineering at Northwestern's McCormick School of Engineering, in partnership with colleagues at NorthShore University HealthSystem (led by Hemant K. Roy, M.D.), combined a polarization-gating optical probe alongside traditional flexible sigmoidoscopy to measure the early increase in blood supply in rectal tissue as a marker for colon cancer. The results are published this month in the journal Cancer Prevention Research.
Flexible sigmoidoscopy is a widely available screening technique that is approved by major guideline organizations. During a flexible sigmoidoscopy exam, doctors use a thin, flexible tube to examine the lower third of the colon. The procedure is an attractive screening mechanism for colon cancer because the test is quick and affordable, can be conducted by a primary care physician and requires simpler bowel preparation than that of a colonoscopy.
However, the test isn't as widely used for colon cancer screening because it only examines a third of the colon, compared to the full colon examination conducted during colonoscopy.
While colon cancer strikes roughly as many women as men, there are significant differences in how the disease presents itself. Women are more likely to have cancerous lesions in the proximal colon, the section of the colon furthest away from the rectum – and the part of the colon that isn't examined during flexible sigmoidoscopy. Due to this discrepancy, previous studies found that flexible sigmoidoscopy alone detected only one-third of colon cancer in women.
A 2009 study in the Annals of Internal Medicine called into question the effectiveness of colonoscopy in detecting proximal colon cancer, which raises concern about the disparity between the effectiveness of colon cancer screening techniques for men and women. Given women's proclivity toward proximal tumors – the hardest to detect using current technologies – researchers are seeking to develop even stronger screening techniques for women.
"Because women are particularly likely to develop cancer in the proximal colon – the hardest to detect – there is a disparity in screening for colorectal cancer in women," says Roy, director of gastroenterology research at NorthShore University HealthSystem. "This study is one of several efforts to apply new technologies to improve our ability to detect cancer, specifically in women."
The researchers hoped that by combining the test with an optic probe that measures how light scatters through tissue would provide a way to measure very subtle changes in the tissue that can indicate the presence of cancer in the organ. The technology makes use of a biological phenomenon known as the "field effect," a hypothesis that suggests the genetic and environmental milieu that results in a neoplastic lesion in one area of an organ should be detectable throughout the organ and even in neighboring tissue. Backman's group has applied a suite of optical technologies to identify signs of the field effect in colon, pancreatic and lung cancers.
"Using these optical techniques, we can identify very subtle changes in tissue that appears to be normal when examined using traditional techniques," says Backman. "This increased level of detail allows us to discover new markers for disease, which we hope will provide new methods to identify cancer in its earliest stages."
In the study of 366 male and female patients, researchers found the performance characteristics of the test to be very promising. The technique identified with 100 percent accuracy each person who had a neoplasia in the proximal colon. 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 cancer and need to be watched closely.
When comparing the results for each gender, researchers found that the early increase in blood supply was a particularly robust marker for proximal neoplasia in women. This result provides hope that the technique could provide a mechanism to improve possible discrepancies in the accuracy of colon cancer screening between men and women.
"Our hope is not to replace the colonoscopy, but to develop better screening techniques to determine who needs a colonoscopy," says Backman. "If we can develop something that can be used by a primary care physician, we can vastly increase the number of people who are screened, and ultimately treated, for this disease."
Megan Fellman | EurekAlert!
Win-win strategies for climate and food security
02.10.2017 | International Institute for Applied Systems Analysis (IIASA)
The personality factor: How to foster the sharing of research data
06.09.2017 | ZBW – Leibniz-Informationszentrum Wirtschaft
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
17.10.2017 | Life Sciences
17.10.2017 | Life Sciences
17.10.2017 | Earth Sciences