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!
A new molecular player involved in T cell activation
07.12.2018 | Tokyo Institute of Technology
News About a Plant Hormone
07.12.2018 | Julius-Maximilians-Universität Würzburg
What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.
Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...
Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.
Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...
New Project SNAPSTER: Novel luminescent materials by encapsulating phosphorescent metal clusters with organic liquid crystals
Nowadays energy conversion in lighting and optoelectronic devices requires the use of rare earth oxides.
Scientists have discovered the first synthetic material that becomes thicker - at the molecular level - as it is stretched.
Researchers led by Dr Devesh Mistry from the University of Leeds discovered a new non-porous material that has unique and inherent "auxetic" stretching...
Scientists from the Theory Department of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science (CFEL) in Hamburg have shown through theoretical calculations and computer simulations that the force between electrons and lattice distortions in an atomically thin two-dimensional superconductor can be controlled with virtual photons. This could aid the development of new superconductors for energy-saving devices and many other technical applications.
The vacuum is not empty. It may sound like magic to laypeople but it has occupied physicists since the birth of quantum mechanics.
06.12.2018 | Event News
03.12.2018 | Event News
28.11.2018 | Event News
07.12.2018 | Life Sciences
07.12.2018 | Materials Sciences
07.12.2018 | Physics and Astronomy