Search

Episode #10 - Guardant 360 - A New Tool in the Cancer-Fighting Toolkit

Steve Abbott:

Well, hello everybody. I don't know what episode of this... Is it 10? Okay. All right because this will be a little bit of a different format, what we're going to do here today. In the past, we really came off of a month worth of prostate cancer topics. When we talked about PSA, what PSA is, the importance of that as a screening tool for early detection of prostate cancer. And we talked about some new developments like the PSMA-PET scan and the importance of that, as far as finding location of cancer and even now potentially to be able to even use it as a form of treatment.What I didn't expect when we talked about that recently, is that we would pretty quickly branch into actual kind of an episode or two maybe, that'll show you that whole process of getting a high PSA result and then how you go about trying to obtain additional information and then find something actionable and do something about it.


Steve Abbott:

So I recently got a PSA result that was up quite a bit. Up significantly, although not a terrifying number in the absolute, but it's up quite a bit. So it had gone from 3.3 to 13.7 in three months. Jill kind of pointed out, I was looking for the hockey stick on the graph, but she says it looks like a ski jumper, which it kind of does actually. A little bit of Olympic sport, especially as the Olympics are getting ready to kick off.


Steve Abbott:

So what we're going to do today is I'm going to actually have my colleague who I pick on probably a little bit too much, actually draw my blood, which is probably not a really great... Hopefully karma doesn't catch up with me on this. But we're going to draw that blood and we're going to send it off the test and I'm going to have Jill talk about that. It's through a company called Guardant, it's a Guardant360. Jill, I'm going to hand it over to you and have you explain a little bit about that and why they call it a liquid biopsy when it's not really what most people think of is a biopsy.


Jill:

So the Guardant360 is a blood test that is drawn and it looks at actually circulating tumor DNA in the blood. And so what a lot of people don't understand is that, the molecular makeup of a tumor is what they're looking at when they do an actual tissue biopsy. And the tumor itself actually does shed some pieces of its DNA that end up in the bloodstream.


Jill:

And so what Guardant360 has done, is they have created a test that is able to pick up that cell-free DNA that's circulating through the blood and they can test that for potential actionable mutations, or for a way to kind of understand that it's a mutation that often there's a treatment associated with. Like I said, it's a simple blood draw, versus having to have an actual biopsy that often is done under anesthesia from the OR or under some form of sedation and the test results come back in about a week.


Steve Abbott:

Okay. And that's already helpful because to tell the truth I'm not sure that I understood that. So it's because of what it's shedding, is similar material that would be tested in the tissue.


Jill:

Correct.


Steve Abbott:

So therefore you don't have to go in and cut anything out or scoop anything out or anything else. You're just finding the same information in the blood.


Jill:

Yes.


Steve Abbott:

One thing I thought I'd heard before, and I'm not sure if this is true or not. Can that also inform, let's say, for example, right now I'm on a drug called apalutamide, the other name for it is Erleada. But does that inform in any way, like say for example, whether certain medications might be helpful or not, or anything like that?


Jill:

So, when we're looking at patients who are currently on treatment, those circulating tumor DNA numbers should go down or disappear. And so if we're doing serial numbers as a mode of surveillance, while you're on treatment, we should not see those numbers start to increase. And so if you're on a medication and we are checking those numbers and we start to see those numbers increase, there would be concern that the treatment potentially is not working like it should be.


Steve Abbott:

Okay. Got it. So maybe at that point you'd switch on to a different drug or combine it with something else or something of that nature.


Jill:

Correct.


Steve Abbott:

Okay. All right. That sounds good. So I think back to our last episode last week, when you dressed me up and made, made me look like a fool. As Grinch.


Jill:

I thought you looked great.


Steve Abbott:

Okay, thank you. And I think back to that, and you had talked about that one of your hopes was that, people would have hope that there's maybe a new paradigm where, you don't think of it in terms of I'm going to die, it's just, I've got something that I got to just manage over time. This is kind of one of those things, right? Where you can find this earlier and say, for example, I did this radiation treatment based off this information in this time last year, but it was a year where I felt great and everything was fine. So maybe the new paradigm is you collect information earlier and in a less invasive way, and you hit it hard and you move on. Right?


Jill:

Exactly. And it's just another tool in our belt. And so the goal of using tests like Guardant360 and the PSMA scanned is to get early answers for exactly what your cancer is doing, and to be able to treat it sooner and potentially have better outcomes.


Steve Abbott:

Okay. And one other thing too, I think it's important. So we're going to go ahead and get my blood here in just a bit, and we'll ship that off tonight. We'll get it back in about a week. Like some other things that are maybe prohibitively expensive, Guardant really works with the patient so that this is not prohibitively expensive. I mean, oftentimes you don't even have a bill.


Jill:

Correct. And Guardant takes care of billing your insurance, the patients do sign the requisition form when the test is sent out, that allows Guardant to submit any additional information needed to get approval from the insurance company. Guardant's test is FDA approved, so quite often insurance does cover it. If insurance does not, Guardant does have a copay assistance program and most patients, the most out of pocket that they would pay is about a hundred dollars.


Steve Abbott:

That's fantastic. That's absolutely fantastic. So we'll go get to work on that. And then meanwhile, I'm kind of still waiting to hear from University of Michigan, I may be heading up there, freeze my well-off in January again, and get the PET scan done up there and then we'll also see how that looks. All right, Chris, take it away, buddy.


Steve Abbott:

So, we're now here in my office here at Cincinnati Cancer Advisors, and what we're about to do is take a blood draw. And the reason why we're going to do that, and we're going to put these results up on the screen so you can see this. It's interesting that we've talked quite a bit in some of our past podcasts about things like, PSA and the new tools that we can use with liquid biopsies and PSMA-PET scans and the like. How little did I know at the time that, this quickly thereafter we'd get a chance to actually walk you through this and see kind of how they work, what these new tools look like. And we'll do it. I'll be the Guinea pig. Because I need to do this anyway.


Steve Abbott:

Chris is going to put it on the screen for you to look at, will be a graph of my PSA results. So what you're going to see is, the graph starts April 2020, and you'll start to see that about August 2020, you'll start to see a pretty steep rise in my PSA. So at this point, likely there's probably solid tumors that are forming, and the sharp increase continued until we got to last November 2020. That's when I went to University of Michigan and had a PSMA-PET scan done. And you'll see that the apex for this topped out at shortly after I finished radiation actually, so my PSA result was over 22 at that point. And that's quite high.


Steve Abbott:

But the good news is you can see the response to the PSMA-PET scan, which was a precipitous decline, all the way back down to 1.3. I think it was, at the beginning of this past summer. Would've been in June. But you can also see that it's headed back up again. And so this last result that I just got last week, it's headed up quite a bit. As I mentioned before, we're going to go out and do a blood draw today, we'll send that off, we'll get results back in seven to 10 days or so. And that'll give us some initial information. And in the meantime, I'll be waiting to hear from University of Michigan, so I can spend some time in tropical, Ann Arbor, Michigan sometime in December or January. And then hopefully that'll highlight or spotlight where those tumors are, and then we can treat them again, like I did this past year.


Jill:

Okay, so a little bit of a review in regards to Steve's treatment journey over the last year. He went up to Michigan and got a PSMA scan, which did light up some early disease. We've talked about it in previous episodes, where based on the PSMA scan results we were actually able to do some targeted radiation therapy, and Steve's PSA stayed stable for a little while. He was being monitored by his treating oncologist. And they were just seeing him periodically and watching those numbers closely. And what we found was that there's been an increase in his PSA level. We're definitely seeing an upward trend.So we did hear from his radiation oncologist and everybody has decided that, now is a good time to re-evaluate and re-establish what Steve's new baseline is.


Jill:

So he is here today. We are going to update a Guardant360. We do have his serial PSAs that we've looked at. And then he is also planning on heading back up to Michigan. We're going to repeat that PSMA scan and then gather all of the data and re-evaluate where we are now, in regards to the activity of his disease.


Jill:

So the Guardant360 is actually a very simple blood draw. You're going to see that based on what we're about to do next. It's just as easy as any of the blood tests that are drawn for any of your typical follow up doctor's appointments.


Steve Abbott:

Okay.


Jill:

If you are a little squeamish and don't like needles, now would be the time for you not to watch.


Steve Abbott:

All right. Hopefully I won't regret giving your mom a hard time on our podcast.


Jill:

What was it that you were saying about Christmas? Count of three. One, two, three.


Steve Abbott:

She's good. I barely felt it.


Jill:

It does help that you have good veins.


Steve Abbott:

Yeah. That's usually not much of a problem.


Jill:

Steve was complaining earlier today, because I did tell him that he needed to limit his caffeine intake as well as increase his water intake for the day.


Steve Abbott:

And I'm going to make it up with wine intake this evening, it'll look just like that blood right there.


Steve Abbott:

So is it just one, like just that vial?


Jill:

Nope.


Steve Abbott:

More than one.


Jill:

We draw two tubes.


Steve Abbott:

Okay.


Jill:

Easy peasy.


Steve Abbott:

It didn't hurt at all.


Jill:

And although it looks like this is a lot of blood, there's only about a tablespoon total between the two.


Steve Abbott:

Are you serious?


Jill:

Mm-hmm (affirmative).


Steve Abbott:

It does look like it's a lot more than that.


Jill:

Mm-mm (negative). And the needle is really small. So you think that this is just absolutely pouring into this tube.


Steve Abbott:

Yeah.


Jill:

It's not.


Steve Abbott:

It's incredible. I would've guessed quite a bit more than that. In a good rich red blood there.


Jill:

It's probably all the red wine.


Steve Abbott:

It probably is.


Jill:

And the dark chocolate.


Steve Abbott:

That's right.


Jill:

No. Or buckeyes.


Jill:

All right.


Steve Abbott:

Thank you, Jill.


Jill:

There we go. All done.


Steve Abbott:

Do you need me to hold that?


Jill:

Nope.


Steve Abbott:

And now we wait.


Jill:

And I did pay attention to the fact that you were wearing a blue shirt. Hence the...


Steve Abbott:

Yeah, oh, look at that.


Jill:

The blue coat band.


Steve Abbott:

I can tell you that the undershirt is almost this exact same color.


Jill:

Of course, it is. All right. We send it off. And then it takes about a week.


Steve Abbott:

Okay.


Jill:

There you go.


Steve Abbott:

And Jill, you mentioned a portal. Is that something I would just set up through Guardant or?


Jill:

So the paperwork that you would've gotten the first time that you had your Guardant drawn. There is a portal that Guardant has, that the patients can actually log into and you get alerted as soon as your results have been entered into the portal. And the nice thing is, and we'll talk about this next week when we have the results. It gives you kind of a graph, very similar to the graph that you get with your PSAs to show you exactly what your results are doing.


Steve Abbott:

Okay. All right.


Jill:

All right.


Steve Abbott:

Now we wait.


Jill:

Now we wait. All right. So what you just witnessed was a wonderful turnabout where I got to stick a sharp object into the arm of The Grinch. We were able to get the Guardant360 drawn. As you witnessed drew two vials, those will be sent off tonight. And it takes about seven days for the results of the test to come back.


Jill:

So the plan will be, we'll get the results of the Guardant and compare that to Steve's previous results. We have his serial PSAs from the last several months. And then, like he said, the plan will be for him to head up to Michigan and have that PSMA scan. We'll use that and compare it to his previous results and all of those data points will be used to determine what the next steps are in his treatment plan. So how are you feeling after the blood draw?


Steve Abbott:

I feel fine. Thankfully, the needle was sharp.


Jill:

They wouldn't let me file it down.


Steve Abbott:

It went in quick and easy. You did a great job. You're a good phlebotomist as they say. But no, it went really, really well. I feel completely fine. It wasn't enough. I think, as you said, it's only like a tablespoon, right? It looks like more, but it wasn't that much. But anyway, I feel completely fine. I'm ready to go home and drink some red wine tonight, eat a good dinner and then we will wait and see what comes back. So we should know that shortly. And we'll go ahead and close this episode out and we'll learn more down the road here just a bit. So thanks everybody for joining and we'll see you next week. Take care.



Recent Posts

See All

Steve Abbott: Hello everybody, and welcome back to episode 19 of CCA's Medical Minute podcast. We are going to do our second round of chemo discussion today, prompted by our new friend, Tina, who aske

Steve Abbott: Hello everybody, and welcome to episode 17 of our Medical Minute Podcast. The first thing I want to do today is welcome a whole lot of new viewers, I hope, at least. So, we went from abo