PAC-MANN blood test shows high accuracy in ID’ing pancreatic cancer
Test may 'enhance' early detection of PDAC cancer type, researchers say
A new blood test called PAC-MANN can detect the most common type of pancreatic cancer with high accuracy, according to a study led by U.S. researchers.
“The PAC-MANN assay is a rapid, high-throughput method that uses small blood volumes with the potential to enhance early [pancreatic cancer] detection,” the team wrote. High-throughput sequencing is used to measure several variables simultaneously, and allows a greater number of samples to be processed at the same time.
Researchers from Oregon Health and Science University (OHSU), who developed the blood test, say it may be a new tool for detecting pancreatic ductal adenocarcinoma, known as PDAC. PDAC is the most common type of pancreatic cancer and is one of the leading causes of cancer-related deaths.
One of the main reasons that PDAC so often turns fatal is that it is often not detected until the disease has already grown to advanced stages, at which point available treatments have limited efficacy. In theory, a blood test that can detect early-stage PDAC could help facilitate earlier diagnoses, thereby allowing treatment to start at an earlier stage and ultimately improving outcomes for patients.
“The problem with pancreatic cancer is that we often catch it too late,” Jared Fischer, PhD, coauthor of the study and a scientist with the OHSU Cancer Early Detection Advanced Research Center (CEDAR), said in a university news story. “Our goal with PAC-MANN is to give clinicians a tool that can detect the disease much earlier, when more treatment options are available and there is a better chance of survival.”
The study detailing the researchers’ work, titled “Early detection of pancreatic cancer by a high-throughput protease-activated nanosensor assay,” was published in the journal Science Translational Medicine.
The PAC-MANN test was developed to detect PDAC by measuring increased levels of protease activity in the blood. Proteases are enzymes that break down large proteins into smaller fragments and are known to become more active in people with this pancreatic cancer type.
Put simply, the test uses proteins that can be cut up by cancer-made proteases, and if the proteins are destroyed, it triggers a fluorescent signal.
This approach has some notable practical advantages, according to the researchers: It requires only a very small drop of blood, and can be performed quickly and cheaply.
“The big difference with this test is the cost: It takes only 8 microliters of blood and 45 minutes to run the test at a cost of less than a penny per sample,” said Jose L. Montoya Mira, PhD, a study coauthor at OHSU and a research engineer at CEDAR.
Montoya noted that the test “could easily be used in rural and underserved settings, where traditional tests are not or cannot be used.”
Our test could be used for people at high risk of pancreatic cancer, which is not targeted by current tests. … It allows for a more robust and less invasive screening, … thus allowing our test to be performed more frequently for earlier detection.
In tests using hundreds of blood samples, the PAC-MANN assay combined with an established marker of PDAC was able to accurately detect early-stage PDAC about 85% of the time, data showed. This test was also 98% accurate at identifying samples from people who did not have PDAC, and it was essentially perfect at distinguishing between people with PDAC and people with noncancerous pancreatic diseases.
“Our test could be used for people at high risk of pancreatic cancer, which is not targeted by current tests,” Montoya said. “It allows for a more robust and less invasive screening, unlike an endoscopic ultrasound and other liquid biopsy tests that require large volumes of blood, thus allowing our test to be performed more frequently for earlier detection.”
Importantly, the team noted, the data also showed a clear difference in PAC-MANN results before and after patients underwent surgery to remove the tumor. Those results suggest that this test could also be used to track outcomes from treatment.
According to Fischer, “this test isn’t just about detection — it could also help us measure how well treatments are working and guide therapeutic options” for patients.
“If we can track a patient’s response to therapy in real-time, we can make better treatment decisions and improve outcomes,” Fischer said.
The researchers are now planning additional clinical trials with the hope of validating their test in people who are at high risk of developing PDAC.
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