|
Topic Name: Detecting pancreatic cancer
Category: Photonics
Research persons: Backman, Yang (lead author), Brand and Roy,
Location: Robert R. McCormick School of Engineering and Applied Science, Northwestern University
2145 Sheridan Rd., Evanston, IL 60208-3100 | Phone: (847) 491-5220 | Fax: (847) 491-8539, United States
Details
Known as a silent killer, with no method of early detection, pancreatic
cancer spreads rapidly and seldom is detected in its early stages. The new
technique could lead to the first screening method for pancreatic cancer in
asymptomatic patients, said Vadim Backman, developer of the technology and
professor of biomedical engineering at Northwestern's
Robert R. McCormick School of
Engineering and Applied Science.
Backman and Yang Liu, a former graduate student of Backman's, teamed up with
physicians at Evanston Northwestern Healthcare
(ENH) to test the technique in a pilot study of 51 patients. The researchers
found they could detect both early- and advanced-stage
pancreatic cancer without touching or
imaging the pancreas.
The extraordinarily sensitive technique, which is minimally invasive and
takes advantage of certain light-scattering effects, can detect abnormal changes
in cells lining the duodenum even though the cells appear normal when examined
with a conventional microscope. The results, published in the Aug. 1 issue of
the journal Clinical Cancer
Research, show that the changes accurately predict the presence of cancer.
More than 30,000 people in the United States die each year from pancreatic
cancer. Count Basie, René Magritte, Billy Carter and Joseph Cardinal Bernardin
all died from it; Luciano Pavarotti is fighting the disease. The overall
five-year survival rate is less than 5 percent; most patients die within the
first two years. If detected early, when the tumor can be successfully removed,
however, the survival rate is 100 percent if a precancerous lesion is found and
50 percent for a stage 1 cancer.
“Using endoscopy and taking biopsies of the pancreas are extremely risky
procedures that are not used on asymptomatic patients,” said Backman. “When a
patient becomes symptomatic, it is too late. This creates a vicious cycle that
we want to break.
“We have found that we can take measurements safely in the duodenum and use a
biological phenomenon called the 'field effect' to our advantage,” he said. “If
you have a precancerous or cancerous lesion in the pancreas, even tissue that
looks normal and is away from the lesion -- including in the duodenum, a
different organ than the pancreas -- will have molecular and other kinds of
abnormal changes. No one can detect these changes earlier than we can.”
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.”
About Researchers:
Vadim Backman
Professor
PhD, Medical Engineering and Medical Physics,
Harvard University - MIT, Division of Health Sciences and Technology
Email: v-backman@northwestern.edu
Phone: (847) 491-3536
Fax: (847) 491-4928
Website: http://biophotonics.bme.northwestern.edu
& Yang (lead author), Brand and Roy
Funded:
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 The Images :
1.Vadim Backman (right) of
Northwestern University and Hemant Roy of Evanston-Northwestern Healthcare
demonstrate a portable version of the new spectroscopy tool, which is showing
promise with colon cancer detection. The researchers are now working on
developing a portable version of the system to aid with pancreatic cancer
detection.
Credit: Northwestern University, Evanston-Northwestern Healthcare
2.Tumors
in the pancreas can not be effectively visualized at the macro or micro level.
Pancreatic tissue is so friable, that sending any kind of instrumentation into
it to explore for cancer would seriously endanger the patient's health. When
compared under the microscope, cells biopsied from the duodenum are identical
between control patients and those with pancreatic cancer. However, when
researchers went one step further and looked at the scale of nanometers, this
very same tissue gave new insight. Photons bounce off tissue at different angles
depending on whether cells are healthy or not. The technique can "see" the
relative difference between healthy and damaged tissue.
Credit: Zina Deretsky and Nicolle Rager Fuller, National Science Foundation
3.Vadim
Backman of Northwestern University led the development of a novel spectroscopy
technology that may aid in the detection of pancreatic cancer.
Credit: Northwestern University, Evanston-Northwestern Healthcare
4.Pancreatic
cancer, unseen at its earliest stages by any other method, can be detected by
examining tissue from inside the duodenum, the uppermost section of the small
intestine. The pancreatic duct communicates with the duodenum via the Ampulla of
Vater. Researchers have shown that cells in a roughly 3 cm radius from this
feature can show signs of the presence of cancer.
Credit: Zina Deretsky, National Science Foundation
5.The
combined four-dimensional elastic light scattering fingerprinting (4D-ELF) and
low-coherence enhanced backscattering spectroscopy (LEBS) technologies were
developed by Vadim Backman and his colleagues at Northwestern University with
the support of seven NSF grants.
Credit: Northwestern University, Evanston-Northwestern Healthcare
6.Researchers
can look at how light bounces off of human tissue to detect subtle changes
potentially caused by cancer. The spectral image that results is like a
fingerprint for disease. The technology was developed with NSF support by
researchers at Northwestern University and colleagues at Evanston-Northwestern
Healthcare.
Credit: Nicolle Rager Fuller, National Science Foundation
|
