Early detection usually offers the best chance to beat cancer. Unfortunately, many tumors aren’t caught until they’ve grown relatively large and spread to other parts of the body. That’s why researchers have worked so tirelessly to develop new and more effective ways of screening for cancer as early as possible. One innovative approach, called “liquid biopsy,” screens for specific molecules that tumors release into the bloodstream.
Recently, an NIH-funded research team reported some encouraging results using a “universal” liquid biopsy called CancerSEEK . By analyzing samples of a person’s blood for eight proteins and segments of 16 genes, CancerSEEK was able to detect most cases of eight different kinds of cancer, including some highly lethal forms—such as pancreatic, ovarian, and liver—that currently lack screening tests.
In a study of 1,005 people known to have one of eight early-stage tumor types, CancerSEEK detected the cancer in blood about 70 percent of the time, which is among the best performances to date for a blood test. Importantly, when CancerSEEK was performed on 812 healthy people without cancer, the test rarely delivered a false-positive result. The test can also be run relatively cheaply, at an estimated cost of less than $500.
Tags: blood test, breast cancer, cancer, cancer blood test, cancer detection, cancer diagnostics, CancerSEEK, clinical study, colorectal cancer, early detection, esophageal cancer, liquid biopsy, liver cancer, lung cancer, machine learning, ovarian cancer, pancreatic cancer, stomach cancer, universal liquid biopsy
When cells die, scissor-like enzymes snip their DNA into tiny fragments that leak into the bloodstream and other bodily fluids. Researchers have been busy in recent years working on ways to collect these free-floating bits of DNA and explore their potential use in clinical care.
These approaches, sometimes referred to as “liquid biopsies,” hinge on the ability to distinguish specific DNA fragments from the body’s normal background of “cell-free” DNA, most of which comes from dying white blood cells. Seeking other sources for cell-free DNA in particular situations is beginning to bear fruit, however. Current applications include: 1) a test in maternal blood to look for DNA from the fetus (actually from the fetal component of the placenta), which provides a means of detecting a possible genetic abnormality; 2) a test in a cancer patient’s blood to look for cancer-specific mutations, as a way of assessing response to treatment or early signs of relapse; and 3) a test in an organ transplant recipient, where increasing abundance of DNA fragments from the donor can be an early sign of rejection.
But recent proposals have been floated about looking for cell-free DNA in healthy individuals, as an early sign of some health problems. Suppose something was found—how could you know the source? Now a team of NIH-funded researchers has devised a new method that uses distinctive features of DNA packaging to provide an additional layer of information about the origins of free-floating DNA, vastly expanding the potential uses for such tests .
Posted In: Science
Without doubt, antibiotic drugs have saved hundreds of millions of lives from bacterial infections that would have otherwise been fatal. But their inappropriate use has led to the rise of antibiotic-resistant superbugs, which now infect at least 2 million Americans every year and are responsible for thousands of deaths . I’ve just come from the World Economic Forum in Davos, Switzerland, where concerns about antibiotic resistance and overuse was a topic of conversation. In fact, some of the world’s biggest pharmaceutical companies issued a joint declaration at the forum, calling on governments and industry to work together to combat this growing public health threat .
Many people who go to the doctor suffering from respiratory symptoms expect to be given a prescription for antibiotics. Not only do such antibiotics often fail to help, they serve to fuel the development of antibiotic-resistant superbugs . That’s because antibiotics are only useful in treating respiratory illnesses caused by bacteria, and have no impact on those caused by viruses (which are frequent in the wintertime). So, I’m pleased to report that a research team, partially supported by NIH, recently made progress toward a simple blood test that analyzes patterns of gene expression to determine if a patient’s respiratory symptoms likely stem from a bacterial infection, viral infection, or no infection at all.
In contrast to standard tests that look for signs of a specific infectious agent—respiratory syncytial virus (RSV) or the influenza virus, for instance—the new strategy casts a wide net that takes into account changes in the patterns of gene expression in the bloodstream, which differ depending on whether a person is fighting off a bacterial or a viral infection. As reported in Science Translational Medicine , Geoffrey Ginsburg, Christopher Woods, and Ephraim Tsalik of Duke University’s Center for Applied Genomics and Precision Medicine, Durham, NC, and their colleagues collected blood samples from 273 people who came to the emergency room (ER) with signs of acute respiratory illness. Standard diagnostic tests showed that 70 patients arrived in the ER with bacterial infections and 115 were battling viruses. Another 88 patients had no signs of infection, with symptoms traced instead to other health conditions.
Tags: acute respiratory illness, Antibacterial Resistance Leadership Group, antibiotic overuse, antibiotic resistance, antibiotic-resistant infections, antibiotics, applied genomics, bacteria, bacterial infections, blood test, diagnostics, gene expression signature, gene signature, genomics, immunology, infectious disease, noninfectious respiratory problems, precision medicine, procalcitonin, respiratory bacteria, respiratory diseases, respiratory viruses, superbugs, Task Force for Combating Antibiotic-Resistant Bacteria, virology, viruses
Just as the computational power of yesterday’s desktop computer has been miniaturized to fit inside your mobile phone, bioengineers have shrunk traditional laboratory instruments to the size of a dime. To assemble a “snap lab” like the one you see above, all scientists have to do is click together some plastic components in much the same way that kids snap together the plastic bricks in their toy building sets.
The snap lab, developed by an NIH-funded team led by Noah Malmstadt at the University of Southern California (USC) Viterbi School of Engineering, Los Angeles, is an exciting example of a microfluidic circuit—tiny devices designed to test just a single drop of blood, saliva, or other fluids. Such devices have the potential to make DNA analysis, microbe detection, and other biomedical tests easier and cheaper to perform.
Posted In: Science