Detection of the biomarker, guanylyl cyclase 2C (GUCY2C), indicates the presence of occult metastases in lymph nodes that may not have been identified by current cancer staging methods, according to Scott Waldman, M.D., Ph.D., chairman of the Department of Pharmacology and Experimental Therapeutics at Jefferson Medical College of Thomas Jefferson University.
According to Dr. Waldman, who is also the Samuel M.V. Hamilton Professor of Clinical Pharmacology in the Department of Medicine at Jefferson Medical College, colorectal cancer that has metastasized, or spread, to the regional lymph nodes carries a worse prognosis and a higher risk for recurrence. However, these metastases are often missed, and the cancer is understaged.
"One of the unmet needs in colorectal cancer is an accurate staging method to determine how far the disease has spread," said Dr. Waldman, who is also director of the Gastrointestinal Malignancies Program at the Kimmel Cancer Center at Jefferson. "The current standard method, histopathology, is imperfect since it only involves looking at a very small sample of the regional lymph nodes under a microscope. There is no way to know whether occult metastases are present in the rest of the tissue."
Dr. Waldman and his colleagues conducted a prospective, multicenter study of 257 patients with colorectal cancer that had no metastases identified in the lymph nodes (node-negative) according to current standards. They analyzed the lymph nodes for GUCY2C expression using a technique called reverse transcriptase-polymerase chain reaction (RT-PCR). This technique, according to Dr. Waldman, amplifies the sensitivity to detect cancer cells compared to histopathology.
The majority of patients – 87.5 percent – had lymph nodes that were positive for GUCY2C. Among those patients, 20.9 percent developed recurrent disease. By comparison, only 6.3 percent of the patients whose lymph nodes were negative for GUCY2C developed recurrent disease.
The patients were followed for a median of 24 months for disease recurrence or death. Indeed, patients who expressed GUCY2C had a shorter time to recurrence and a shorter disease-free survival. The prognostic value of the marker persisted even after a multivariate analysis that took other known prognostic factors into account.
According to Dr. Waldman, 20 to 30 percent of patients diagnosed with node-negative colorectal cancer experience disease recurrence within five years. This is approximately the same rate of recurrence as that for some categories of patients diagnosed with node-positive disease. These observations suggest that there are occult metastases in the lymph nodes of node-negative patients at the time of diagnosis. GUCY2C specifically identifies these occult metastases that indicate risk for recurrent disease.
"Beyond predicting disease recurrence, detecting this biomarker could be useful for identifying patients who might benefit from treatment with adjuvant chemotherapy, which is specifically given to patients with node-positive disease," Dr. Waldman said.
Emily Shafer | EurekAlert!
More genes are active in high-performance maize
19.01.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn
How plants see light
19.01.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
19.01.2018 | Materials Sciences
19.01.2018 | Health and Medicine
19.01.2018 | Physics and Astronomy