Devin Airey: When I talk to healthcare leaders about scale, they think, maybe this is right or wrong, you can tell me, that that means that we should all be at scale together. So everyone who has $100 should get their whole genome sequenced. Is that the right way to think about scale and how does Quest play in here?

Mark Gardner: For most laboratories it's very difficult for them to even acquire a sample. It can cost well north of $100 to get blood drawn, to put it in the right container, to ship it, to so-called "accession" it, which is a fancy word for to make sure that you have the right sample and that it can be tracked in the system. And if it costs $100 to do that for an average sample and it costs a hundred dollars to do the sequence, well, why would you keep accessioning a sample if the endpoint of germline genomics is the whole genome? Your genome doesn't change. It's the same from womb to tomb. And so why continue to repeat something that you've already done once?

When it comes to areas like cancer, there's an added element to that where a lot of the same things we talk about in genomics don't necessarily apply because cancer is always a subsection of the entire genome that you're trying to measure because if the majority of you was cancer, then you would be dead. So we are constantly looking at the so-called needle in the haystack because the cancer represents the needle and the body represents the haystack.

Airey: I think that's a great tee up to Dan here, leading Haystack Oncology for several years and then coming into the Quest Diagnostics family very recently, how are you all bringing other innovations like liquid biopsy in helping those integrate genomics into oncology care, cancer care specifically?

Dan Edelstein: The innovation with Haystack Oncology is not only liquid biopsy and the approach to measuring, as Mark just mentioned, identifying that needle in a haystack. Those rare molecules that are in circulation that are derived specifically from the tumor, but using those molecules to help the physician and the patient better understand information about their cancer.

For example, many of the patients in the clinic today who have been diagnosed are asking some very basic questions about whether the treatment they have been on has been successful and whether their cancer is responding to treatment and if they have responded, if the cancer has returned.

So I think it's kind of an application where we're looking at the genomic information that Mark just mentioned where it can be used for therapy selection, so identifying specific variants that are useful for a specific therapy or sensitizing to a specific treatment.

And then there's the general concept of looking at fragments of DNA derived from the tumor to better understand how patients are responding. Traditionally that's done with radiography. It's done with protein biomarkers, both lack a certain sensitivity that we've seen over the last decade or so. Protein biomarkers are associated with cancer, they're not causative for the cancer so sometimes they're elevated in patients that don't have cancer. We know, for example, that ctDNA is a specific marker for the cancer, and when we measure it, the innovation at Haystack is doing so with really a refined sensitivity and specificity.

Airey: I do want to back up for a moment though and make sure that we're clarifying some of the concepts and definitions language that we're using for our audience. So could you describe briefly what a liquid biopsy is?

Edelstein: If we think about what a biopsy is, biopsy for a patient with cancer would be some mechanism to access the cancer. So typically it can be done with a needle, it can be done through a surgical biopsy. It's a pretty invasive procedure where the patient has to basically go into surgery of some sort or interventional radiology to access the cancer.

What we know about a liquid biopsy is these can use this technology to access the tumor through a blood draw. So it's not necessarily non-invasive, minimally invasive in that the patient has to go into a blood draw center and have submit a few tubes of blood for analysis. And in doing so, we're able to measure molecules that are shed from the cancer in that blood tube.

Airey: So if I summarize here, liquid biopsy is an example of an innovation that can enable this genomics at scale, this third era of genomics. You were starting to talk about the ability to bring more information to the patient. So I want to pause and talk a little bit about how these innovations can help and drive the context for our patient individually, and then of course across their entire cancer journey. How does genomic testing fit into a patient's cancer journey?

Gardner: There are a lot of things that can be tested for, everything from what is your risk of getting cancer that you may have inherited from your family background. For example, everyone's familiar with the BRCA gene, which confers a risk for breast cancer. It actually confers a risk for other cancers as well, but nonetheless, it's most associated with the breast cancer.

Cancer in and of itself is a disease of damaged DNA. That is one of the hallmarks of what cancer is. And so all cancers have variants between the cancer cells and the rest of your body. And so these technologies, as they've advanced, enable you to separate those variants that are occurring in the cancer and contrast those with those that are in the rest of the body. And that's a very specific personalized marker of the presence of cancer in the body.

And so at its core, that's what a lot of these methods of trying to do early detection or early screening are trying to do. Some of them are more focused on methylation, which is not quite the same as a variant in the classical sense, but it is a marker of something is going on to change the original DNA.

To what we're doing with MRD testing or minimally residual, minimal residual disease or molecular residual disease. People use both of those terms where because the half-life of cancer DNA is only about two hours once a cancer cell dies and its DNA is shed into the bloodstream, it's only with you for a couple hours.

So an MRD, if you're measuring something and you know what to look for between the baseline of what that cancer fingerprint is versus the rest of the body. And if it's still there after a few days post-surgery then this person still has some cancer somewhere in the body. It doesn't isolate exactly where it is, but that they still have something going on.

Edelstein: Add just kind of to summarize, it's basically an excellent biomarker to kind of provide that level of precision for patients that are undergoing surgical resection. Just to kind of put it in the context of the patient physician after a patient, let's say with stage two colon cancer has undergone surgery, there's a very open question as to whether or not that patient should undergo treatment with additional chemotherapy to potentially eradicate disease. That decision is made based on pathological staging.

And what happens in a pathology lab is somewhat of a static entity, but it informs the recurrence risk to some degree for patients, and it informs to a degree, but lacking some precision, how much chemotherapy a patient should receive. And so what we can do as Mark mentioned, is measure a few days, couple weeks after surgery, the presence of circulating tumor DNA, and if we don't see it and the appropriate test is used, we have more certainty that patient's surgery was successful. If we do see it, then that patient would benefit from additional treatment to eradicate any of the residual disease in their body.

Gardner: I think it's very exciting because historically we've been limited to, a tumor has to be about one centimeter in size to be able to see it via imaging. Well, by the time a tumor gets to be one centimeter in size, there's literally billions of cells. You're not fighting against a lone ranger out there. And remember, one of the hallmarks of cancer is unconstrained growth. So a billion cells can make a billion copies in a hurry. And I think just because it's small to the eye doesn't mean that it's not dangerous. And that's why cancer frankly has been such an incredible foe to humanity because these things that start as one centimeter in size can be lethal within a matter of just a few months. Having to wait until something gets to be one centimeter in size, it's just too close to lethality.

Whereas through this liquid biopsy method where we're able to pick up even just trace amounts of recently deceased cells, that enables you to measure much lower levels of cancer size than one centimeter and sometimes can give you months of time of a head start to treat that patient.

There's an old saying that I learned from Dr. Dan Van Hoff, although frankly I think a lot of people use this expression, but I'm grateful to him for it which is, the patients are waiting. The second somebody finds out they have cancer, their whole life is consumed with worry over this. Their family's whole life is consumed with worry over this. And so having real time data is incredibly valuable for these folks.

Airey: We have early diagnosis, faster results, more confident results, fewer unnecessary treatments that all sound like a slam dunk for the patients. Kind of a no-brainer, but I look back on all my years in healthcare, I know there's not a whole lot of slam dunks that exist for real. And so what barriers come up when you work with providers and organizations bringing this to the patients, using this in their workflow, and what's Quest's role in removing those barriers on behalf of those providers to make sure that they can actually use it for all the patients that need it?

Gardner: The largest role we have is 92% of all covered lives in the United States have a contract with Quest Diagnostics. So one of the main barriers is, do I have insurance? Who's going to pay for all this? Obviously, cancer is a very expensive disease to treat, and nobody wants to go through this uninsured. Nobody wants to go through this where somebody's asking you, "Hey, we have this really important information for you, but you're going to have to pay for it yourself."

And so the thing that I'm super proud of with Quest is that we have built a relationship with payers over the years where they know that we give good value for appropriate testing. That's one of the hallmarks of our brand as Quest Diagnostics. And payers trust us.

So we're not covered yet for MRD, but we're obviously in the process of working on the steps to get that done. But I'm confident that Quest will be able to get private payer coverage and Medicare coverage for this type of testing wherever it's appropriate.

Edelstein: Yeah, I'd say back to Devin your question with the barriers. There's two, right? There's two general barriers. One is logistics and kind of ease of use on the patient physician administration side for a health system and the other is confidence in the test. And so the physician and the patient both feel confident that this is the right test because there are a number of tests out there.

Back to Mark's point, Quest's integration with pathology, and the fact that there are, how many pathologists are at Quest processing tissue, Mark?

Gardner: 420.

Edelstein: 420. So that is a heck of a number. And that means that Quest is processing a number of tissue pathology samples in patients that have cancer. And that we've heard over the last five, six years is one of the biggest challenges in just easing the logistics because what we do, as Mark mentioned, is we first sequence the patient's primary tumor or metastatic tumor site. And that informs the liquid biopsy test that we design for each patient.

So in some scenarios, that first tissue sample can be a bottleneck. I think that's where Quest has great access and can enable this to move in a much more streamlined fashion.

The other piece is this the appropriate or the right liquid biopsy test? And having been in this field for over a decade, over 15 years, there was a lot of proving that needed to be done let's say in 2010, 2011, that liquid biopsy, that you could actually detect ctDNA and that ctDNA was representative of the patient's cancer. There was a huge burden of proof about a decade ago, and that's been largely demonstrated. So now where we are is in a space where there are multiple different options available to the patient and clinician, and it really comes down to the performance and then the level of clinical data supported by the performance of a particular assay.

Airey: So should every payer be covering this? Should all employers make sure that liquid biopsy is a part of their benefits?

Gardner: Well, I think that really depends on the cancer type right now. The clinical utilities proven pretty well for colorectal cancer. It's been proven pretty well for breast cancer. It's been proven in some bladder cancers.

We're obviously committed to making sure that it's proven in other cancers as the science allows it. But I would say that as Dan mentioned, there are other competitors out there. If you kind of look at the analyst reports and what's being said, this is probably the most rapidly adopted technology I've ever seen in the world of the intersection of genomics and oncology. I think about a third of all oncologists are using this today, and so usually it does take payers a little while to catch up with the clinical practice, but I think that they're doing so.

Genetic and genomic test utilization has increased astronomically, with over 50,000 new tests introduced in the U.S. in the last decade. Find out why this market is growing and how it is diversifying. Explore four key drivers behind the boom in the genetic testing market and what they mean for the rest of the healthcare industry.