Currently a diagnosis of pancreatic cancer is almost always a death sentence. Pancreatic cancer causes little or no symptoms until it has spread and mutated so much that it can't be stopped. If we could only diagnose this cancer much sooner the potential exists to go remove it in a small area and get a cure in most cases. Well, some scientists and technologists at Northwestern University have discovered that a biopsy of the duodenum (the top part of the small intestine which the stomach empties into) can provide a method to do very early diagnosis for pancreatic cancer.
EVANSTON, Ill. --- Optical technology developed by a Northwestern University biomedical engineer shown to be effective in the early detection of colon cancer now appears promising for detecting pancreatic cancer, the fourth most common cause of cancer deaths in the United States.
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, which will be published in the Aug. 1 issue of the journal Clinical Cancer Research, show that the changes accurately predict the presence of cancer.
So they developed a better way to examine cells to identify abnormal cells. Then they used that better technology to examine duodenal cells because it is easier to reach the duodenum to get the cell sample than it is to reach the pancreas. Luckily, the duodenum shows abnormal cells when the pancreas (which connects to the duodenum) has early stage cancer cells. All very good.
What I want to know: How did they reach the duodenum? Can this be done by snaking a tube through the mouth and down through the stomach?
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.
This pair of optical tests also produced excellent results in detecting colon cancer.
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.
What I want to know: How often would we need to get tested for pancreatic and colon cancer to assure that new cancers would always get caught at early enough stages to be curable? How fast does a pancreatic cancer pass through its first stage into later stages? My guess is that the answer varies considerably from case to case.
What we really need are cancer tests for the entire body that can work pretty close to continuously. Imagine an injection of a cancer detection nanobot that would produce a visible symptom (how about blue and green spots on your hand or face?) when it found a cancer. Then a blood sample could isolate some nanobots and an instrument could download the collected information from the nanobots.
We face another problem with highly sensitive techniques for early cancer detection: We have lots of very small cancers in tiny nodes that are stuck at very small sizes because they have not mutated to generate new blood vessels (ie they do not secrete angiogenesis compounds). The most sensitive methods imaginable for detecting cancers would detect too many. The vast majority of detected abnormal cells would not constitute a threat - at least not for many years. Attempts to find and remove all these very small cancers would involve surgery on many organs and the little cancer nodes might be hard for surgeons to find. So we need cancer finding technology that can discriminate between high and low risk cancers.
|Share |||Randall Parker, 2007 August 05 07:26 PM Biotech Cancer|