The Impact of Decipher Biopsy Testing on Clinical Outcomes in Localized Prostate Cancer – Randy A. Vince Jr.

January 23, 2022

Daniel Spratt and Randy Vince discuss the impact of Decipher Biopsy testing on clinical outcomes in localized prostate cancer. This conversation starts off with a background on Decipher Biopsy testing and how it is used for men with prostate cancer. This then transitions into a discussion on the controls and background of how the study was set up. Dr. Vince then discusses some of the main findings of the study, showing that men with high-risk Decipher Biopsy scores were independently associated with shorter times to treatment failure. As the conversation progresses, Dr. Vince discusses different studies that look at Decipher Biopsy testing in men with prostate cancer. This conversation concludes with a conversation about how Decipher Biopsy testing should be used to stratify and organize treatment plans for different patients.

Biographies:

Randy A. Vince Jr., MD, Fellow of Urologic Oncology, Department of Urology, University of Michigan, Ann Arbor, MI, USA

Daniel Spratt, MD, Vincent K. Smith Chair in Radiation Oncology, University Hospitals Seidman Cancer Center, Case Western Reserve University School of Medicine, UH Cleveland Medical Center


Read the Full Video Transcript

Daniel Spratt: Thank you so much for joining us here at UroToday. My name is Dr. Dan Spratt. I'm a professor and chair of radiation oncology, at UH Seidman Cancer Center, here in Cleveland. And it's my great pleasure to invite Dr. Randy Vince, who is just completing his urologic oncology fellowship at the University of Michigan and is soon to be faculty, here at UH Seidman/Case Western urology department. We're very excited for him to join. And he'll be discussing today, so it was very late breaking and important work, on the use of genomic classifier, in a prospective statewide registry. And so, Dr. Vince, take it away.

Randy Vince: All right. Thank you, Dr. Spratt. It's a pleasure to be here to present some of our work, so I thank you for the opportunity. To get started, I have no disclosures.

So as a background, Decipher Biopsy is a commercially-available gene expression classifier. And it's intended use, is to assist with risk stratification of men with newly diagnosed localized prostate cancer. However, the majority of studies evaluating the utility of Decipher Biopsy have been retrospective. So there remains a need to evaluate the clinical utility of this assay, using prospectively collected data. And so this what we aim to do, using data from the Michigan Urologic Surgery Improvement Collaborative.

Just a little bit of information about MUSIC. It consists of both academic and community urology practices. As such, it incorporates over 90% of all urology practices in the state of Michigan. And it maintains a prospectively collected data registry. And every practice has trained data abstracters, who have specialized training, and they input data from the time of diagnosis.

For our study cohort, we analyze men who underwent Decipher Biopsy testing from February 2015 to December 2019, giving us a multi-institutional cohort of 855 men. Median age was 66 years old. And 81% of the men had less than, or equal to, grade group three disease.

Our primary endpoints were, time to treatment, which was for all men who were initially managed on active surveillance, the time to progression, to definitive treatment.

The second endpoint was, time to treatment failure. We defined this as, time from treatment completion, to either the biochemical recurrence, or receipt of salvage therapy.

Additionally, we looked at the correlation between Decipher Biopsy scores and commonly used clinical variables.

To first highlight some of our results, the correlation between Decipher Biopsy scores and commonly used clinical variables. Which you can see here, is that Decipher Biopsy scores are on the Y axis, and those commonly used, or traditional clinical variables, are our X axis.

As we look at the correlation, we see that the median Decipher score, and commonly used clinical variables, that as the disease aggressiveness increases, so does the median Decipher Biopsy score for that group, like you can see here, for NCCN risk scores. But I think, just as interesting, we see a great amount of heterogeneity in Decipher Biopsy scores within each risk grouping. That goes to say, that everyone with favorable intermediate disease does not have high, or intermediate, risk Decipher Biopsy scores. There were a good deal with low-risk Decipher Biopsy scores, as well.

So moving on, to our first primary endpoint, time to treatment. All patients who were initially managed with active surveillance, we evaluated the amount of time spent on active surveillance, before transitioning to definitive therapy. What you can see here, is that those men with high-risk Decipher Biopsy scores, had a shorter time to treatment, compared to those men with low or intermediate Decipher Biopsy scores. In fact, the median time on active surveillance, for those men with high-risk Decipher Biopsy scores, was 13.6 months, compared to 33 months, for those men with low or intermediate Decipher scores.

Additionally, on multivariable analysis, we found that those men with high-risk Decipher Biopsy scores, were independently associated with the progression from active surveillance to definitive treatment.

For our next endpoint, time to treatment failure, we examine the time from treatment completion, until biochemical recurrence, or receipt of salvage treatment. As you can see here on this plot, those men with high-risk Decipher scores, experience a shorter time of treatment failure, compared to those men with low or intermediate Decipher Biopsy scores.

So similarly, on multivariable analysis, we see again, that a high-risk Decipher Biopsy score, is independently associated with a risk of treatment failure.

So in summary, those men with high-risk Decipher Biopsy scores, spent significantly less time on active surveillance, compared to those with low or intermediate risk scores. Additionally, those men with high-risk Decipher Biopsy scores, had greater rates of treatment failure, than those with low or intermediate scores.

And so, this just, again, summarizes our data. The high-risk score, those patients spent less time on active surveillance, and had a shorter time to treatment failure, as compared to those men with low or intermediate risk Decipher Biopsy scores.

So future steps include, the G-MAJOR Trial, which will provide level one evidence to the impact of genomic testing on clinical decision making.

Daniel Spratt: Thank you so much, Dr. Vince. That was incredible work, and very informative. And some questions for you, in terms of how we use this data going forward. To recap, these were patients treated as routine standard of care that got these tests. Right? This wasn't part of some clinical trial. So now, looking back at the data, so let's say you have a patient that has, let's say, a favorable intermediate-risk disease, like a Gleason three plus four, that you're considering active surveillance on, but you end up getting a high Decipher score. How does that impact your thinking, or your decision making?

Randy Vince: Yeah. So that's a great question, Dr Spratt. And I think, as clinicians, we have two primary responsibilities, specifically, us who treat prostate cancer. First, is the role of an educator. And so this means that we have the responsibility to give patients as much information as possible, to allow them to participate in shared decision making process. And we want them to be as knowledgeable as possible, as they enter this process. The second is, providing the best quality, and most technically sound treatment, whether you're a surgeon, or a radiation oncologist.

So with that being said, I do believe, there's a litany of data, outside of a clinical trial, that support Decipher testing in a correct clinical setting. So that patient, that you presented, with favorable intermediate disease, and a higher to score it, that is the patient who will benefit most, in my opinion, from Decipher Biopsy testing.

What our data just shows, is that not all patients with favorable intermediate disease will have the same Decipher Biopsy score. And so, that can provide another piece of information to the patient and to clinicians. And for me, personally, that patient, given our data, and other data that is out there, regarding Decipher Biopsy testing, I would discuss and highly recommend, that patient undergo definitive treatment, or definitive therapy, rather than active surveillance.

Daniel Spratt: Yeah. And I'd agree. That's exactly, how I view it. And with your data, the chance of that patient being on active surveillance in two years from now, very, very low.

Randy Vince: Correct.

Daniel Spratt: And what's amazing is, that despite this relatively favorable cohort, that already, you can see differences in biochemical recurrence, so early on.

Randy Vince:  Yes.

Daniel Spratt: So then, to flip it is, low-risk prostate cancer. Right? We have got a lot of studies that didn't use genomic testing. Outcomes are good, long term, but that's with a lot of men coming off of active surveillance. Right? And sometimes, rapidly. Somewhere between 40, 50, 60% of men that go on active surveillance, end up coming off, at some point. And so if you had a low-risk patient, especially, if it was, let's say, a higher volume, low-risk patient, or a higher PSA density, but it had a high Decipher score.

Randy Vince: Mm-hmm (affirmative).

Daniel Spratt: How do you think of that situation?

Randy Vince: Yeah. So, I think, again, that is a discussion I would have with a patient, to let them know, given this high-risk Decipher score, this may indicate that your disease is more aggressive, than what we've been able to find out. The one thing I think that, at least to me, that gives strength to the Decipher testing is, it goes against the narrative that I hear from a lot of clinicians who treat prostate cancer. And that is, when you do genomic testing, you only get the sample from the biopsy core. And to me, that's, at least I think about it, and I think that's slightly flawed. Because if that was the case, then every Gleason six prostate cancer should have around the same Decipher Biopsy score, and should have around the same clinical behavior. And we just know that, that's not the case.

And so, using that information, and knowing that isn't the case, I would discuss that with patients and say, "Hey, the chances of you coming off active surveillance within the next year or two, is substantially higher, given this high-risk Decipher Biopsy score." I have to weigh in the risk and benefits of all the different management options, that if they chose that, to that they wanted to pursue active surveillance, I wouldn't say, "Absolutely not." But at the same time, I would let them know that I would keep a closer eye on them, and probably, do a more intense active surveillance regimen. Knowing that, the chances of them progressing to definitive management are substantially higher.

Daniel Spratt: Yeah. No, I also completely agree. I think it's tough, because most of the data we have for active surveillance is in, we call, low volume, or very low-risk disease, but there's a general pressure, we'll say, that all low-risk men, we should put on active surveillance. And that's how I practice, personally. But as we get better, whether it's genomics, or MRI, it begs the question to a patient, and especially, for a radiation oncologist. Whereas, as the disease gets more aggressive, we sometimes, have to add on hormone therapy. If a patient has a high probability of coming off surveillance, and they've got a lot of anxiety or concern about biopsies, it's just, I think there's some nuance that sometimes, exactly how you're saying, that gets missed.

Randy Vince: Mm-hmm (affirmative).

Daniel Spratt: So, another question here, Dr. Vince, is Decipher testing, right. Is this something that every single patient, no matter what, should get a reflex test? How do you view this type of test?

Randy Vince: Yeah. So to the short answer is, in my opinion, no. The more detailed answer is, for those patients who, like those that fall in favorable and immediate-risk, where we know there's clinical heterogeneity there, and that everyone with this risk, it falls in this risk stratification, will not have disease that behaves the same way. Those are the patients, in my opinion, who can benefit from having Decipher testing. Those patients with very low-risk disease. I don't think they should undergo Decipher testing, because I don't think that it adds anything, when it comes down to the ultimate decision making process. And especially, when we are talking about pursuing active surveillance, versus definitive therapy.

Daniel Spratt: Yeah. No, and I also agree. I think, guidelines agree with what you're saying, in that very low-risk disease. Typically, there's not really any evidence that any additional testing, right, probably, really makes a big impact. But these patients could progress to, let's say, favorable intermediate, and then at that point, it's become the question.

Well, I think, that's very informative for all the listeners. And it's great work, again, from certain real world data and patients, to see how they do, and really, how impactful, potentially, this test is. People always are going to want to say, these tests do cost, these tests cost money. I think, they're all covered by Medicare.

Randy Vince: Mm-hmm (affirmative).

Daniel Spratt: I know another area of your interest is in prostate cancer disparities. What do you feel, in terms of the next steps are, to make sure that there's equitable use of these tests? And I know that wasn't looked directly at, in this study, but just any comments on that?

Randy Vince: Yeah. I can answer that question in two different directions. One is from a clinical perspective, the other is from a research perspective.

From a clinical perspective, I think, unfortunately, there are a lot of clinicians who are just stuck in their ways, when it comes down to the advice and treatment that they recommend. And so, as such, they are very hesitant for using tools that they haven't done much research on, even though there's a litany research out there. And so, I think, educating those clinicians, or attempting to educate those clinicians, might increase the number of Decipher Biopsy testing done in the clinical setting. That's just one potential solution there.

But from the research perspective, this testing platform gives us so much data. And we know that prostate cancer is very hereditary, and there's multiple genes that influence, not only the development of prostate cancer, but the aggressiveness of it.

And so from that perspective alone, as someone who is very passionate about disparities, I hope, that we can increase the number of testing, the number of tests performed, as it gives us a more diverse patient population to investigate potential causes of prostate cancer, and just looking at gene expression. And another step that, to me, that just makes sense to go a step beyond that, is then now, tying in how societal factors influence gene expression. All of these things will allow us to close some of these gaps that we see, when it comes to prostate cancer outcomes, in my opinion.

Daniel Spratt: Yeah. That was spot on. Could not agree more. So, all right. Well with that, thank you so much, Dr. Vince. It's a true pleasure. And thanks, everybody, for listening.

Randy Vince: Thank you, Doc Spratt.

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