Liquid biopsy for cancer detection catching on fast. You choose: simple blood test, or invasive solid tissue sample?


The News:

Until recently, cancer detection depended on invasive solid tissue sampling that didn’t provide a complete picture. Now, a budding cluster biotechs is making it easier to detect cancer early with liquid biopsies.

Evelyn Warner at points out that, “The notion that a person’s blood can reveal a wealth of health information looked so shiny that a company leading the charge, Theranos [Palo Alto CA], was valued at $1 billion at its peak in 2014. It has since come crashing down, as the company recently listed its lab space for rent. Another jaw-droppingly well-funded company is Grail [Menlo Park CA], which has so far raised over $1 billion to develop its own liquid biopsies–but its promise has yet to bear fruit.”

Many companies have seen success in the field of cancer diagnostics utilizing conventional, tried-and-true technologies.

On the other hand, “Oncology leads the way in blood diagnostics,” Dr. Ewan Hunter, Director of Business Development and Head of Statistics at UK-based Oxford BioDynamics PLC, said.

Warner reports that Hunter’s company analyzes the environmental impact on the genome in the form of epigenetic DNA modifications. These modifications can then be used to screen for cancer, among other things.

Another company, Qiagen NV (Venlo, Netherlands), recently became the first to enter the European lung-cancer market with its DNA-based technology: Therascreen enables VEGFR-based stratification of patients to determine if they are eligible for AstraZeneca PLC’s (London) Iressa. The product has since become the gold standard used in a majority of labs and clinics.

Meanwhile, Angle PLC (Guildford UK) has developed its own impressive test based on entire cells instead of fragments of DNA of dead cells, and it stands to become the new “go-to” for ovarian cancer.

So why did liquid biopsy development start in oncology?

“The starting point to determine what’s possible is clinical need, and that’s currently personalizing care for people with cancer,” Andrew Newland, CEO of Angle, tells Warner. Immuno-oncology therapies work for some but not all, and they’re expensive. “We have to ensure that the right patients receive the right therapy, and the way to do that is via liquid biopsy,” he continued.

Traditionally, testing is performed with antibodies, but some cancers don’t have all the necessary surface markers, which the antibodies target to give a readout. Solid biopsies also have a major limitation: they can only be taken once, making it impossible to track progression over time.

This is because tumors are heterogeneous and their genetic makeup changes over time, so the second sample won’t match the first. And if that’s not reason enough, solid biopsies are also highly invasive.

Liquid biopsies, on the other hand, can be performed with a routine blood draw, and the technology has progressed so far and fast that various tests are now already on the market. Furthermore, these tests are at the forefront of the wave of personalized medicines.

“We’re moving towards more targeted therapies by understanding molecular mechanisms,” said Michael Kazinski, Senior Director of Head of Global Product Management Sample Technologies at Qiagen. He adds, “the best way to personalize a treatment in such a manner is to start with a liquid biopsy.”

Steve’s Take:

Like a lot of boomers, twice a year I go to a lab in my hometown of Encinitas, CA, and submit to what I simply refer to as a blood test. I sit quietly while the technician draws four vials of my blood, after which I get an email from my primary doctor saying there’s generally nothing worrisome in the test results. I usually then go to a portal called “My Chart” at the UC San Diego Medical Center’s website and peruse the actual results.

There are four categorical batches of tests results: there’s the lipid panel, the glycosylated HGB (A1C), the comprehensive metabolic panel and the CBC with ADIFF. I don’t pretend to understand most of what’s displayed on my monitor. Instead, I’m relieved that the results fall into the “normal” range, meaning there are no red flags.

How does all this tie together with the recent appearance of the liquid biopsy on my personal radar screen? Two reasons.

Number one. Regretfully, there’s practically no one in my family and/or other social realm who hasn’t had some type of cancer, especially skin cancer. I’ve lost track of how many procedures I’ve had to remove just the basal-cell variety (so far, luckily, given the decades of outdoor running). In each case prior to the surgery, there was a biopsy.

When I hear the word “biopsy,” I immediately tend to think of a minor procedure in which a small piece of tissue is removed from the patient for further investigation. But a “liquid” biopsy is less invasive than a surgical biopsy. In fact, a liquid biopsy usually involves just taking a blood sample, although a urine or saliva sample also falls into the same category.

Number two. I’ve heard it said by medical professionals that “your blood tells a story.” And that is precisely why liquid biopsy is a hot topic in oncology today. It opens possibility, access, and understanding into the world and makeup of cancer cells. MyOncoPath explains that liquid blood biopsies are another genetic test to help understand individual cancers and move into precision, personalized medicine and away from the one-size fits all approach to treatment plans.

Elaborating on The News section, liquid biopsy is a blood test to look for cancer DNA circulating in a patient’s bloodstream. The blood biopsy can detect epidermal growth factor receptor (EGFR) gene mutations from the tumor DNA that is shed into the bloodstream. Blood samples can be spun down to plasma to be analyzed for tumor DNA followed by genomic sequencing. As with tumor profiling, liquid biopsies can unveil mutations changing the cancer’s sensitivity or resistance to certain therapies.

Liquid biopsies have been used for early cancer detection (at this time the technology is not 100% but researchers are hoping to develop liquid blood biopsies into an early cancer screening test). For existing patients, it can assist in treatment planning, determining how well a treatment is working, gauging resistance or if a relapse has occurred.

Regular liquid biopsies can create an enhanced understanding of a specific cancer, its genetic makeup, molecular changes, and response to treatment. With the results of a liquid biopsy doctors can potentially select an optimal treatment plan for a specific patient based on the biomarkers found in their cancer’s cells.

Dr. Nikhil Wagle, of the Dana-Farber Cancer Institute, hopes ultimately to use blood biopsies to guide how he treats patients. Say a biopsy finds that the amount of tumor DNA in the patient’s blood is rising again.

“That tells me, ‘Oh, no, the tumor is growing again,’” Wagle said. “Maybe then I look at what the composition of that tumor DNA is again, and it tells me either what different regimen to use or what additional drugs to add.”

Liesbet Lagae, PhD, is co-founder and currently Program Director of the Life Science Technologies at the Interuniversity MicroElectronics Center (Leuven, Belgium). She notes:

“Cancer specialists have discovered that the blood of cancer patients differs from the blood of healthy people. As a result, oncologists can detect all kinds of indications in this ‘different’ blood that can help with the diagnosis and treatment of cancer. For instance, they may find tumor cells in the blood that have separated from the original tumor (that may be in the lung tissue, for example). They are called ‘circulating tumor cells’, or CTCs.”

Bottom Line:

I boil all this down to the following question: Would you prefer your healthcare team treat you based on the average response to your general cancer type? Or to have a tailored treatment plan based on the genetic biomarkers of your cancer and its response to therapies?

Steve's Take: I'm sold on #LiquidBiopsy as a promising development in the fight against #cancer Click To Tweet

Today, liquid biopsies are a non-invasive alternative to surgical biopsies. They eliminate many of the challenges of tissue or tumor biopsies for patients, such as cost, pain, access and risk. And most importantly, they are thought to be a significant stride forward in the way we understand and treat cancer.

This is an exciting, promising development. I recommend that if you find yourself faced with the need for a biopsy, speak with your doctor about the applicability of the liquid variety. Considering all the additional, potentially crucial data it may present, all it requires is a blood test. I’m sold.

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