Molecular Biomarkers in Localized Prostate Cancer Guideline

An interview with Dr. Scott Eggener of University of Chicago Medicine on "Molecular Biomarkers in Localized Prostate Cancer: ASCO Guideline." This guideline provides recommendations for available tissue-based prostate cancer biomarkers geared toward patient selection for active surveillance, identification of clinically significant disease, choice of postprostatectomy adjuvant versus salvage radiotherapy, and to address emerging questions such as the relative value of tissue biomarkers compared with MRI.

Read the full guideline at www.asco.org/genitourinary-cancer-guidelines

TRANSCRIPT

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Hello and welcome to the ASCO Guidelines Podcast Series brought to you by the ASCO Podcast Network, a collection of nine programs covering a range of educational and scientific content and offering enriching insight into the world of cancer care. You can find all the shows including this one at podcast.asco.org. My name is Shannon McKernin. And today I'm interviewing Dr. Scott Eggener from the University of Chicago Medicine, lead author on molecular biomarkers in localized prostate cancer ASCO Guideline. Thank you for being here today, Dr. Eggener.

Thanks for having me, Shannon, and covering the guideline.

So first, can you give us a general overview of what this guideline covers?

Yeah, this guideline has been two years in the making and is an overview of the available molecular biomarkers to help clinicians and patients make smart decisions for men with localized prostate cancer. And that's in the newly diagnosed setting, as well as for certain patients that have undergone surgery and are considering adjuvant radiation therapy.

And so what are the key recommendations for this guideline?

So there was a lot of data that the team looked through with the help of the ASCO home office, and a Herculean amount of work went into it. There's a lot of commercially available tests out there. Most of them are quite expensive. And we are trying to make sense of the available literature and provide a guide to clinicians on what these tests are, which patients they might be relevant for, and how to interpret them.

The key takeaways that the data that's been published for most of these biomarkers are purely prognostic. And there is good science and good data supporting them. But they have not been embedded in a rigorous fashion or within trials or validated to have the highest level of evidence. However, they can be used in certain situations to add additional info for the patient and clinician to try to make smart decisions based on prognostic information.

Another key recommendation is that there are select patients that these can be helpful for. And we dive into a lot of the details on who these patients may be. Number one is a patient newly diagnosed with prostate cancer who is trying to determine whether to do treatment of the prostate cancer or embark on active surveillance. And some of those decisions are relatively easy and straightforward.

But when the clinician and the patient are looking for all pieces of information to influence one way or the other, genomic or molecular biomarkers can be useful at that critical fork in the road. However, we made it very clear multiple times throughout the guideline that our group's recommendation is that the biomarkers should not be reflexively ordered for every individual newly diagnosed with prostate cancer. It seems wasteful and not an appropriate use of resources.

The other situation clinically where these can be used are for men that have had previous surgery and are considering secondary radiation therapy, which can be given in an adjuvant or salvage manner. And there are some data suggesting that a specific test by Decipher, a genomic classifier, can be used to help inform whether adjuvant radiation would be appropriate or not.

So that was a good overview. And this guideline also includes some special commentary sections with additional research questions that the expert panel wanted to address. So can you tell the listeners a little more about these important considerations?

Yeah, it's critically important to know that these tests are not black and white. And they don't always clarify a data-based path forward. But we tried to emphasize in many different areas that integrating genomic or molecular information can be integrated into optimizing decisions.

And the special commentary really dives into a lot of those details on working with the pathologists on selecting the appropriate biopsy sample to send to one of these laboratories. It gets into some of the specifics on interpreting the data, as well as the role of CLIA-approved labs and non-CLIA-approved labs for certain staining that's done internally within organizations or with biomarker panels.

And so would you be able to expand a little more about which patients may benefit from having molecular biomarkers?

Yeah, the sweet spot for some of these biomarkers include a couple different patient groups. The first one is what I alluded to earlier-- the man newly diagnosed with prostate cancer deciding whether to do active surveillance, which is a monitoring program, or to have treatment of the prostate typically by either surgery or radiation therapy.

Again, worth emphasizing-- these tests are not appropriate for every newly diagnosed patient. And I would argue even for the man deciding between surveillance and treatment, there are specific men, perhaps those with higher volume low risk prostate cancer or lower volume favorable intermediate risk prostate cancer, that provides the ideal patient that may benefit from some of these tests.

The second clinical scenario that was discussed amongst the group were patients where treatment intensification might be valuable. Again, these biomarkers are purely prognostic, and there's no high level evidence suggesting that treatment intensification leads to better outcomes. Although intuitively, the higher risk profile a patient has, either by clinical factors or biomarkers, there is a conceptual rationale that treatment intensification might prove beneficial.

And the third category of patients that may benefit are those who have had prostatectomy where the pathology shows some adverse features, and there's a high likelihood of recurrence, and the clinician's decision is to guide the man on whether pure adjuvant radiation in the setting of an undetectable PSA or early salvage therapy at the time of biochemical recurrence would be more valuable. And there is one test that is commercially available that can help inform that decision.

Great, so finally, what do you envision as the future of molecular biomarkers for localized disease?

As we took an overview of the landscape in 2018 and 2019 of these molecular biomarkers, much of the group thought this was version 1.0 or 2.0 in this space.

And it is our hope and likely scenario that not only will we have better data on some of the currently available biomarkers with higher levels of evidence from either correlative science from randomized trials or formally embedded into randomized trials, but also that there's a large amount of work being done to improve the quality of biomarkers and that, in the future, we'll see improvements on the currently available ones or newer biomarkers coming around that will be valuable for these men as they make decisions along their prostate cancer course.

Great. Thank you for your work on this important guideline. And thank you for your time today, Dr. Eggener.

Thank you, Shannon.

And thank you to all of our listeners for tuning into the ASCO Guidelines Podcast Series. To read the full guideline and find additional resources such as the guideline's pocket card, go to www.asco.org/genitourinary-cancer-guidelines. And you can find many of our guidelines and interactive resources in the free ASCO guidelines app available on iTunes or in the Google Play Store. And if you've enjoyed what you've heard today, please rate and review the podcast and be sure to subscribe so you never miss an episode.