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Conversations With Prostate Cancer Experts


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Prostate Cancer Dormancy + Disseminated Tumor Cells

Dr. Julio Aguirre Ghiso is a Professor of Medicine, Hematology and Medical Oncology and Oncological Sciences at Ichan School of Medicine at Mount Sinai in New York City. His research explores why and how in some patients disseminated tumor cells can remain dormant for years after initial treatment before reactivating to form incurable metastases.

Prostatepedia spoke with him about his research and about a clinical trial testing his findings that is currently looking for prostate cancer patients.

To  learn about a clinical trial for prostate cancer patients that Dr. Aguirre-Ghiso is running: Join us or download the issue.

Why did you become involved in cancer research? What is it about cancer research that has kept you interested?

Dr. Julio Aguirre-Ghiso: When I was an undergraduate student, I was looking for challenging problems to solve in biology. Serendipitously, I started working and volunteering for a cancer biology team in Argentina, where I trained. I became very interested. I was working on tumor immunology. Then I became very interested in the cell biology of cancer cells. At some point, I realized that it didn’t really matter if it was cancer or Alzheimer’s or some other basic biological questions on other organisms; what I really was curious about was solving tough problems and answering questions. This was a good mix where, if I were able to do it, I would also be helping people with cancer in the future.

Focusing on cancer would give me an opportunity to apply my curiosity to something that is relevant for people. That was the original intention. Since I was not an MD, my curiosity was about mostly biological questions. This was a fitting problem to go after.

Let’s talk about the concept of disseminated tumor cells. Can you explain to us how that works and how it is related to the development of metastasis?

Dr. Aguirre-Ghiso: Patients usually present with what’s called a primary tumor. That’s the first cancer lesion ever found in that patient. At that time, doctors will do certain tests on that primary tumor to understand if it had gone through certain changes that would make it able to spread. When cancer cells grow, they may acquire certain abilities that allow them to spread from that primary site—from, let’s say, the prostrate or the breast—to other parts of the body.

The disseminated tumor cells are these cells that have spread throughout the body. They have disseminated from the primary tumor to other organs in the body. Those could be the bones; the liver; the brain; or the lung. When they arrive to those organs, they’re not immediately able to grow. Since they’re usually solitary cells–that’s how we find them in the patient samples and in the mouse models that we’ve used—we call them disseminated tumor cells. They’re not yet metastases, but they’re not in the primary tumor. They’ve left and arrived to other organs. That’s the definition of these disseminated tumor cells.

Why are they important? We and others have provided compelling evidence that these cells are the source of the metastases. Those are the cells, not all of them, but some of them, that are able to eventually grow into metastases that affect the functioning of the organ, and sometimes systemically, the functioning of the patient. That’s what leads to death. That’s why these cells are important.

Do all disseminated tumor cells eventually grow into metastases?

Dr. Aguirre-Ghiso: No.

How do you know which disseminated tumor cells are going to grow into metastases and which are not?

Dr. Aguirre-Ghiso: Well, that’s been a major challenge and a major push from my program: to try to get in early and identify those disseminated tumor cells so that we have some idea if a patient carries disseminated tumor cells that are not going to do anything and the patient doesn’t have to worry, or if the patient carries some cells that look like they’re switching and they’re going to form metastases.

That has been our goal. It’s not yet a clinical test, but that’s why we have pushed the boundaries of our research to get to that point as fast as possible because we think that instead of waiting and not doing anything or treating blindly and then waiting until those metastases grow, we can intervene earlier. We would like to be able to say that this patient has only dormant cells and they don’t look like they’re going to reactivate based on certain markers or gene signatures.

That patient would then only need to be monitored, but new treatments may allow eliminating even those cells. If another patient has a mixture of cells some of which are fully dormant and some of which look like proliferative cells, we would treat him in a different way.

We have provided data for this from our mouse models and from clinical patient samples in prostate cancer. We published two papers in 2014 and in 2015 on this.

Not all cells are going to grow.

In fact, if you look at early lesions in breast cancer, for example, disseminated tumor cells are found in the bone marrow of 13-15% of women with ductal carcinoma in situ but only a small fraction of that 13-15% will develop metastases. It’s not a given that if these cells are there they’re going to grow, but if they are there, there is a higher risk of metastases. That has been proven by large population studies that have been published in The New England Journal of Medicine. This is true for not only breast cancer but for other cancers as well. The goal and the challenge is to have enough information to be able to predict accurately what those cells are going to do when you detect them.

Where we are in the timeline of being able to predict which patient is carrying potentially dangerous disseminated cancer cells and which is carrying dormant disseminated cancer cells?

Dr. Aguirre-Ghiso: We have different areas of research into these disseminated tumor cells. Why they are dormant? Why do they sleep in the body for a long time and then awaken? We discovered a marker in 2015 that could distinguish these deep-sleeping cells in both prostate cancer and breast cancer models. If the cells had this marker, they would behave in this dormant way, and if they didn’t have this marker, they would look more like a proliferative or an about-to-reactivate cancer cell.

At that time, it was correlative between just two groups of patients. Last year, we published a paper on breast cancer where we used the same marker detected in tumor cells disseminated to the bone marrow of breast cancer patients. We were able to show that if patients had this marker they were much less likely to relapse with bone metastases than if they didn’t have this marker. In 2015, we’ve published the original finding where we just said this is probably a good marker; we understand how it works in mouse models. In 2018, we showed that the presence of the markers can distinguish retrospectively how patients behaved. Now the challenge is for people to start using the markers prospectively to see if it helps them make decisions on how to treat or monitor patients. We are very much at the early stages of applying the information that we have generated and bringing it into the clinic.

On the other hand, in that same 2015 paper, we were able to show that if we use two drugs that are FDA-approved and combine them in sequence, we can turn on these dormancy mechanisms in different types of cancer cells—i.e. breast, prostate, and head and neck cancer cells. Because these drugs were available—and there are independent studies showing that when prostate cancer patients are treated with hormonal therapy and anti-androgens, they turn on this marker of dormancy that tells you the cancer is deciding to go into sleeping mode— we wondered if we could repurpose those drugs and treat prostate cancer patients at risk of developing metastases to see if we could delay the onset of metastasis and keep the disseminated tumor cells in a dormant state.

To read the rest of our conversation and to learn about a clinical trial for prostate cancer patients that Dr. Aguirre-Ghiso is running: Join us. Or download the issue.


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Dr. Bertrand Tombal On Making Prostate Cancer A Chronic Disease

Dr. Betrand Tombal, Chairman of the Division of Urology at the Cliniques universitaires Saint Luc and Professor of Urology at the Université catholique de Louvain (UCL) in Brussels, Belgium, is the current President of the European Organization for Research and Treatment of Cancer (EORTC), the leading European academic research organization in the field of cancer.

Dr. Tombal is keenly interested in treating advanced prostate cancer and in the development of hormonal treatment and new biological agents

Prostatepedia spoke with him about how newer agents like Zytiga (abiraterone), Xtandi (enzalutamide), and Erleada (apalutamide) have changed the prostate cancer arena.

Join us to read the rest of this month’s conversations about Zytiga, Xtandi, and Erleada.

How have the newer agents, like Zytiga (abiraterone) and Xtandi (enzalutamide) changed the treatment landscape for men with castrater esistant prostate cancer?

Dr. Tombal: These drugs changed treatment in three ways. First, urologists know that hormone therapy may have a profound effect on some patients. Having said that, in the late 90s, we had hormone therapies of limited efficacy. For better or worse, there was no regulatory platform development for historical hormone therapy, so we are missing good evidence that they increased overall survival or even significantly delayed progression. These two new hormones build upon things we already knew for years, but they are far more effective, and more importantly, they have been developed following a strong regulatory context so that we know exactly their benefit.

But before that, the Taxotere (docetaxel) story was interesting for me because that’s one of the first studies I participated in. Seeing all these guys dying from prostate cancer, I thought it was unbelievable that we could increase overall survival. I was thus extremely surprised that urologists in charge of managing advanced prostate cancer at that time would negatively react to chemotherapy and claim that the benefit was limited and toxic. Hence, patients would be referred by the physicians. I thought that was strange. From day one, I thought that we should ask what the patients think. But the landscape changed again when we saw the results of the post-chemotherapy trials with Zytiga (abiraterone) and Xtandi (enzalutamide), how much they increased overall survival, and their major effect on PSA. We realized that we had game-changers.

But to me, changing the game was not necessarily about having patients live a little bit longer. I always go back to the many discussions I have had with patients who ask not whether they will live longer but if they will live better.

That’s why I was so excited about being one of the Principal Investigators on the Prevail trial. The Prevail trial was really not about Xtandi (enzalutamide); we already knew the drug worked. Prevail was about having a discussion early on in the course of the disease, when the patient was becoming metastatic and castrate-resistant. We would ask: what do you want to do? Do you want to wait a bit and only start chemotherapy after you’ve got symptoms? Or do you want to start the drug immediately?

The patient would then ask about the side effects. I would say that there are side effects, but to give it a try, and if they didn’t want to live with them, we could simply stop the drug and the side effects would go away. These are oral drugs, so if you have side effects that are severe, you can just stop the drug.

That’s what was new, that not only could we help the patient live longer, but we could delay complications of the disease and buy him quality time It has really changed the way we treat patients.

If you look at newer trials, like Prosper and Spartan, they are having the same discussion but going one step further.

You have no metastases, but your PSA is progressing rapidly. What do you want to do for the rest of your life? Do you want to do nothing, enjoy a few additional months until you develop metastases and then start the treatment? Or do you worry enough that you would like to try one of these drugs to see if you tolerate it? To me, it’s no more complicated than that. These drugs, Zytiga (abiraterone), Xtandi (enzalutamide), and now Erleada (apalutamide), have brought the possibility of discussing early on in the course of the disease what is important for that particular patient. Do you want to delay progression? Because in the end, these drugs are not very toxic.

That’s why these drugs are so important.

And this is just the beginning. We’re not going to speak four years from now about giving Xtandi (enzalutamide) or

Zytiga (abiraterone) in the metastatic castrate-resistant prostate cancer space because we’re going to give these drugs earlier and earlier to patients with high-risk disease together with radiotherapy and surgery. We have a chance. What we want is to have prostate cancer patients die from something else.

A few years ago, Andrew C. von Eschenbach, a urologist that became the twelfth Director of NCI, said that his grail was to make cancer a chronic disease. That’s what we’re doing with these newer drugs: we’re making prostate cancer a chronic disease. We have never said we were going to make someone immortal, but hopefully we still delay the appearance of metastases and symptoms, so that they will die from something else. That’s the beauty of trials like Spartan, Prosper, and (hopefully) Aramis in which Xtandi (enzalutamide), Erleada (apalutamide), or darolutamide are given at early signs of rapid PSA progression to delay the metastases. We used to say that at that stage of the disease, everybody will die from prostate cancer, but now we’re delaying progression so much that patients are going to start dying from something else and not have to go through all of the suffering associated with prostate cancer. That’s a major change. That’s the change these drugs are bringing. They bring the possibility of intervening early and making prostate cancer a chronic disease. And yes, there is a slight increase in toxicity. And yes, at a huge increase in cost. But that’s how the world is.

Do you think it’s of any concern that we don’t really understand the longterm impact of these drugs?

Dr. Tombal: When people discuss this aspect, they assume that we have effective treatments to treat the progression. That’s not true. It’s the same with bone-targeted therapy. I remember when bone-targeted therapy came on the scene, a famous medical oncologist said that what we are delaying is simply giving a little bit of cheap radiotherapy to the spinal column (on the lumbar spine). I said that was true, but you assume that cheap radiotherapy to the spinal column is effective. And it is not.

When are bone-targeted therapies like bisphosphonates and Xgeva (denosumab) traditionally used, and how has their use changed now that these newer drugs have come onto the scene?

Dr. Tombal: Less frequently. And that’s a major drama. Once again, it comes from a wrong interpretation of the data, from that oncological view that overall survival drives all decisions. When the major study on zoledronic acid and Denosumab was published, people said it doesn’t make patients live longer or increase overall survival. I said that I didn’t care: increased survival is not what we expect from this drug.

What we expect from this drug is that it delays skeletal complications. It reduces the total number of bone complications in a patient’s lifetime. This means that, if you’re a gentleman of 70 years, and God has written in your book that you’re going to live another two years, you’ll get your first skeletal event in 12 months. Xgeva (denosumab) will not make you live longer, but it will delay your first skeletal complication to 16 months. Once again, you’re buying quality time. You define that quality time as time without bone complications.

Then came Taxotere (docetaxel), Xtandi (enzalutamide), and Zytiga (abiraterone). They all extend overall survival and skeletal events. Physicians are starting to not prescribe these drugs because they say we don’t need them now that we have Zytiga (abiraterone) and Xtandi (enzalutamide).

Recently, Bayer conducted a clinical trial comparing Xofigo (radium-223) plus Zytiga (abiraterone) versus Zytiga (abiraterone) alone. The trial ended after a little more than one year because there was a significant excess of fractures and death. One of the striking observations is that only one-third of the patients in the trial received bone-protecting. The European Medicines Agency’s statement says that, most likely, this excess of fracture happens only in patients not receiving bone-targeted therapy. Clearly, avoiding bone-targeted therapy has been a big mistake. We believe that if we have drugs that increase overall survival, we don’t need bone-targeted agents. But now we realize that if patients live longer with bone metastases, we increase the likelihood that they’re going to have complications. These drugs are even more important than they were before.

Would you say that most men on drugs like Zytiga (abiraterone), Xtandi (enazlutamide), or Erleada (apalutamide) should consider bone protecting therapy?

Dr. Tombal: If they have bone metastases, I would say yes. The question then becomes what to do if you only have one bone met. In Europe, we use a lot of modern imaging technologies, such as PSMA and whole-body MRI. Sometimes, you see a man with a rising PSA and one or two bone mets that you don’t see in a bone scan. If that man has two, three, or four bone metastases that show signs of progression, such as increased alkaline phosphate, he should be on bone-protecting agents.

What sort of combinations do you think seem the most promising or have the most benefit?

Dr. Tombal: At this point in time, we have failed to show that any combination is better than a single agent for prostate cancer. When I’m speaking about combinations, I’m speaking about combining drugs to increase overall survival.

When Taxotere (docetaxel) came out, there was an epidemic of shotgun experiments where everybody tried to combine Taxotere (docetaxel) with all sort of agents, all usually having shown a strong rationale in the lab. Not one of those trials was positive. Most of them showed a benefit in favor of Taxotere (docetaxel) alone. When Bayer said we’re going to combine Zytiga (abiraterone) with Xofigo (radium-223), that seemed like low-hanging fruit. They were combining two drugs with different modes of action and different toxicities that both showed an increase in overall survival when used alone. Nobody could have imagined that it would end in catastrophe—that combining the two agents would shorten survival.

At this point in time, there is not a single indication that one combination is better than a single agent in prostate cancer.

What should patients take away from that?

Dr. Tombal: These agents: Zytiga (abiraterone), Xtandi (enzalutamide), Erleada (apalutamide), Taxotere (docetaxel), Jevtana (cabazitaxel), and in the United States, Provenge (sipuleucel-T), have been used sequentially, but not in combination. Combinations don’t have any benefit.

Do you think that is because there is some synergistic effect in terms of side effects?

Dr. Tombal: I have absolutely no idea. That’s where we stand today.

Do you have any thoughts for men who’ve been prescribed Zytiga (abiraterone), Xtandi (enzalutamide), or Erleada (apalutamide)?

Dr. Tombal: I would say that one of the great messages of the Prosper and Spartan trials is that we probably do too much imaging, that it’s probably better to follow a patient just with PSA. Then when his PSA starts to increase rapidly, that is probably the time to talk about earlier treatment with one of these agents. That is when to have the overall discussion about what you want to do and where you want to go.

Why shouldn’t we use imaging as much?

Dr. Tombal: Because we are tempted to offer additional treatments, such as radiotherapy, which have limited value, when we have at least five or six large Phase III trials that establish the philosophy of starting Zytiga (abiraterone), Xtandi (enzalutamide), and Erleada (apalutamide) earlier.

In Europe, we do a lot of imaging and a lot of salvage treatment. But we have to be honest, it’s driven by belief more than data.

Europe is ahead of the United States in that regard.

Dr. Tombal: Being ahead has started to make us realize that we probably over-treat more patients than we help.

That’s a huge issue because men can live for a long time with often debilitating side effects.

Dr. Tombal: Exactly.

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3 or Fewer Prostate Cancer Mets

Dr. Piet Ost is a radiation oncologist at Ghent University in Belgium. His work focuses on post-surgery radiation therapy and metastasis-directed therapy for oligometastatic prostate cancer, or a cancer recurrence with three or fewer metastases.

Prostatepedia spoke with him about treating men with so few metastases after treatment.

Can you define oligometastatic prostate cancer?

Dr. Ost: First of all, if your doctor talks about oligometastatic disease, I think it’s very important to ask them what they mean by that? When we look through literature, there are several definitions used.

Some people use oligometastatic while others use oligorecurrence, synchronous metastases, or low volume metastases. Many of these probably mean the same, but there is no uniform definition.

In 1995, Hellman and Weichselbaum first defined oligometastases as metastases limited in number and location. These tumors have not developed the full capacity for metastatic growth. It could be an issue with the metastases—or the seed—or it could be an issue with the soil—the environment in which the metastases started to grow. That’s the biological definition.

This is not very useful as a clinician. What is limited? Is that a certain number? If you look through literature, many clinicians define it as up to three metastatic lesions with no more than two different organs involved. That is probably the most used definition, but there are alternatives. Some say that it’s only one metastasis while others say it’s as many as five or even 10 in case of brain metastases. Some say there has to be a certain amount of time between primary diagnosis and the occurrence of metastasis.

There’s a lot of confusion throughout the literature. If you read an article, you have to look at their definition. When doctors talk to each other, and when patients talk to each other, they all use the word oligometastatic, but it might be that they’re talking about a different disease.

Is there any sort of restriction on where those metastases are located—for example, in only the pelvic area?

Dr. Ost: At this time, I don’t think so. It’s a biological phenotype. We care less where the metastasis occurs. For example, we have had patients with unique lung mets at the time of recurrence where we remove those lung mets, and then these patients remain disease-free for many months or even years.

Normally, when you have a patient with lung mets, those are visceral mets, and their prognosis is supposed to be very poor no matter what. There appears to be a subset of patients with a limited number of metastases, even visceral metastases, who still benefit from removing or irradiating the metastases. We have several of those cases documented already. It’s not about the location. It’s something about the biology, and that is the big problem at this time.

Currently, when we propose a certain oligometastatic or metastasis directed therapy to a patient, we don’t know if the metastases we see and treat are the only ones there, or if three months after we remove or eradiate them, there will be 20 new metastases. We don’t know that at the start. This shows us that imaging is still far from perfect and sometimes we only see the tip of the iceberg.

When we look at the distribution or pattern of metastases in recurrent prostate cancer with Choline PET/CT and PSMA PET/CT imaging, we see that, after receiving prior prostate cancer treatment, the majority of patients relapse first in the lymph nodes.

That is mainly in the pelvic lymph nodes. If we look at all the patients that we screen for now, 70% have nodal recurrences, 25% have bone metastases, and 5% have visceral mets. If we look at all of those recurrences, two thirds of those relapses are what we call oligometastatic, meaning up to three metastatic spots. We don’t believe that there is a true limitation on the organs. How it evolves is actually a fingerprint of the disease.

When you start, you don’t know whether it’s a true oligomet. We cannot predict at this time how the disease will evolve.

How do you normally treat oligomets? With radiation or surgery? How do you decide which is most appropriate?

Dr. Ost: We still counsel our patients on the standard options. For patients with upfront metastatic disease, the landscape has changed dramatically where we now introduce Androgen Deprivation Therapy (ADT) plus Taxotere (docetaxel) or ADT plus Zytiga (abiraterone) as a standard of care.

We still do not know if these options are helpful in treating the primary tumor and its mets with metastatic-directed therapy. In situations with upfront oligometastatic disease, we counsel our patients that the standard of care is systemic drugs while the addition of any metastatic-directed therapy is one big question mark. We do not advise it outside clinical trial.

The situation is a bit different in the recurrent setting. In the recurrent setting, there’s a gray zone. For example, the older data said that starting ADT for a PSA relapse following primary therapies—just starting ADT—is not advised; it’s better to wait and see and do a delayed ADT at the time of symptomatic progression.

Now with the very sensitive imaging, we see mets earlier at PSA relapse. What should we do with these? Do we still say the standard of care is wait and see, ADT, or something else? Because new imaging created this gray zone, all of a sudden we saw a boom in these oligometastatic patients, so we decided to do a clinical trial in this setting.

In our paper published in The Journal of Clinical Oncology (JCO), we randomized our patients to wait and see. One group had surveillance while starting ADT, and the other group had surgery or radiotherapy to the mets followed by surveillance. In that study, we found that surgery or radiotherapy is better at postponing further progression to polymetastatic disease rather than just observing patients.

We have an alternative now in counseling patients: metastaticdirected therapy with either surgery or radiotherapy. We know that it’s very safe, because we did not see any grade 2 or higher toxicity, which is a positive thing to tell men with prostate cancer. We can offer you something without a whole lot of toxicity. We still have to tell you this was a Phase II trial. The endpoint was time to progression.

I’m still not sure that giving metastatic-directed therapy will change your disease in the long run, that it will make you live any longer compared with immediate ADT or surveillance. It’s still too early to tell. We try to counsel our patients with these different options.

Join us to read the rest of Dr. Ost’s comments. (Subscribers can read the conversation in their March issue of Prostatepedia.)


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Dr. Piet Ost: Why Medicine?

Dr. Piet Ost is a radiation oncologist at Ghent University in Belgium. His work focuses on post-surgery radiation therapy and metastasis-directed therapy for oligometastatic prostate cancer, or a cancer recurrence with three or fewer metastases.

Prostatepedia spoke with him about what drew him to medicine.

Why did you become a doctor?

Dr. Piet Ost: It was a bit by coincidence. I planned to be an airline pilot, but due to some medical issues with my eyes, I was not allowed to fly. I’ve always had a big interest in anything scientifically sound where you can start with science and build up from there. I found evidence-based medicine interesting from the beginning. So I started an alternate plan to become a doctor. I enrolled in medical school and became more interested in getting patients involved in the science, in applying evidence-based medicine. How can we do that? Where are the big gaps in science?

In medical school, I realized that there are so many unanswered questions that patients ask on a daily basis. You just have to tell them what we know now, but that there are many things that we still do not know or fully understand. That communication process has helped me a lot in talking to patients. They helped me grow in this process once I graduated.

Subscribe to read Dr. Ost’s comments on oligometastatic prostate cancer.


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Dr. Charles Ryan: Why Oncology?

Dr. Charles J. Ryan is the Clinical Program Leader for Genitourinary Medical Oncology at the University of California, San Francisco Helen Diller Family Comprehensive Cancer Center.

He primarily treats men with advanced prostate cancer. His research focuses on novel therapies for advanced prostate cancer.

Not a member? Join us to read Dr. Ryan’s conversation in our March issue on cancer recurrence.

Why did you become a doctor?

Dr. Ryan: I grew up in a medium-sized city called Appleton, Wisconsin. My father was the first medical oncologist and the first prescriber of chemotherapy in our town. He never did a fellowship because they didn’t exist when he finished his training.

I’m the youngest of four kids. By the time I was in junior high school, all of my siblings had gone away. My mother is a nurse, and she was working for hospice in our community. Sitting around the dinner table, it was just the three of us.

The dinner conversation was frequently about cancer, hospice, medicine, and things like that. That’s what shaped me at the time. I decided to become a physician in college, but I had given a lot of thought to oncology and medicine well before making the decision.

I guess medicine is the family business?

Dr. Ryan: Yes. It is sort of a family business. When I started my medical training, I felt a kinship with the medical oncologists I interacted with at the University of Wisconsin. I was randomly assigned to work in an oncology clinic and a prostate cancer clinic. I just felt like: these are my people. The timing was right for me to make a decision. It’s what I wanted to do with my life. I found the disease itself biologically compelling, and the emergence of new therapies and the community of physicians and researchers who worked on it were an interesting group of people. It was a natural decision.

Join us to read Dr. Ryan’s thoughts on Xtandi (enzalutamide) and Zytiga (abiraterone.)


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Advanced Imaging + Prostate Cancer

Dr. Phillip Koo is Division Chief of Diagnostic Imaging at the Banner MD Anderson Cancer Center.

Prostatepedia spoke with him about advanced imaging + recurrent prostate cancer.

Not a member? Join us to read more about recurrent prostate cancer.

Do you have any advice for men considering advanced imaging for prostate cancer?

Dr. Koo: We’ve been talking about better imaging tools for prostate cancer for years. When it comes to other cancers, we moved forward a great deal when FDG PET/CT became available. With prostate cancer, we’ve been stuck with CT and bone scans since the 1970s. They’re great tools. I don’t want to devalue what they’ve done for our patients since then, but we knew we could do better. Urologists and oncologists knew patients had metastatic disease, but our imaging tools limited detection.

We have new tools available to us in 2018. There is no question that costs are going to be higher, but that shouldn’t stop us from exploring and pushing the envelope. The whole purpose is to improve overall survival and treatment for our patients. An ounce of diagnosis could be a pound of cure. If we could identify disease sooner, identify the right patient for these exams, and use them at the right time, then we could probably create treatment plans more appropriate for patients with better outcomes. It’s something that I firmly believe. There is so much potential here.

When radiology is practiced in a vacuum, it’s not as powerful as when it’s integrated into patient histories and treatment plans. Radiology is a very powerful tool. But we often think of it as a commodity, something that does not have any distinguishing value. That is a huge under-estimation of radiology.

When performed correctly in a multidisciplinary setting, with access to the medical record and physicians who are taking care of the patient, radiology unlocks information that can really impact care for patients with prostate cancer. And we are currently only scratching the surface. This will change as analytic tools continue to analyze bigger data sets that include imaging and clinical data. If a urologist determines that their patient needs imaging, they’re going to write a request for imaging that describes what type of test they want and why they need it.

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Patients often go to the closest facility. Convenience is important, but when it comes to certain tests or exams, I urge patients to seek out subspecialized radiology experts and facilities with the experience and expertise in the performance and


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Imaging + Prostate Cancer Recurrence

Dr. Phillip Koo is Division Chief of Diagnostic Imaging at the Banner MD Anderson Cancer Center.

Prostatepedia spoke with him about imaging recurrent prostate cancer.

Not a member? Join us to read more about recurrent prostate cancer.

Prostatepedi:Some imaging occurs when men are first diagnosed. When, after treatment, do they encounter these newer imaging techniques? After a high PSA reading? Or just a part of routine follow-up?

Dr. Philip Koo: That’s a really tough question because imaging has a role throughout the continuum of care for any prostate cancer patient. Screening currently isn’t done with imaging, but there are a lot of research studies looking at it.

Prostate MRI is most often used for the detection of local disease. Oftentimes, patients with a rising PSA and a negative standard biopsy might get an MRI or an MRI-guided biopsy.

Bone scans and CT scans are used to help detect metastatic disease. There are many different scenarios, but usually after patients are diagnosed with cancer, most will visit radiology if there is a suspicion for metastatic disease. If we refer back to the RADAR 1 paper published in 2014 by Dr. Dave Crawford in Urology (see Urology 2014 Mar; 83(3): 664-9), we talk about imaging patients at initial diagnosis and imaging those who are intermediate or high-risk. In those patients, we recommended a bone scan and a CT scan.

Patients who are biochemically recurrent may also be imaged. Again, MRI will often be used to look for locally recurrent disease. Bone scans and CT scans are used to look for metastatic disease.

What about some of the newer imaging techniques?

Dr. Koo: The newer techniques are exciting. In both the patient community and the scientific community, we’ve heard a lot about these tools over the past decade. They weren’t widely available, especially in the United States. These newer imaging tools are simply better, which is why there is so much excitement. They will pick up more sites of disease at lower PSA levels.

When we do detect sites of disease, they’re more specific. Our confidence that these sites are actually disease is higher than our confidence when we’re using traditional bone and CT scans. These tests perform at a higher level compared to standard imaging.

Another benefit to these new tools is that in one single exam, we’ll be able to detect soft tissue and bony disease.

How do these newer techniques change treatment? If you can pick up the disease at a lower PSA is that going to change how a doctor treats a man?

Dr. Koo: Yes. We will be able to detect disease sooner. Currently, these newer imaging techniques are used mostly in patients with biochemical recurrence. When a patient has biochemical recurrence and we see the PSA rise, our standard imaging techniques are often not good enough to detect metastatic disease. The problem is that the radiation oncologist or the urologist needs to decide how they want to treat the patient.

Using these newer tools, we can provide the urologist or radiation oncologist with better information about whether or not the disease has spread at the time of biochemical recurrence. If it has not, and the urologist can perform salvage cryotherapy or a radiation oncologist does salvage radiotherapy, we could potentially cure the patient.

Really?

Dr. Koo: You’re hitting the disease before it spreads, so theoretically yes. These newe imaging techniques do better, but we really need to prove why this is important and how this impacts care. The answers to these questions will solidify the utility and value of these imaging techniques for prostate cancer patients.

If a patient gets the Gallium-68 PSMA or Axumin scans will his local urologist or oncologist know what to do with that information?

Dr. Koo: Maybe. The problem is that all of this sounds great: we have a tool that can detect disease sooner, better, and more accurately. But then the more important question is what to do with that information and does it impact outcomes. If we don’t know, then what is the value of that imaging tool? We operate under the assumption that earlier detection is always better, but we’re learning that in a lot of diseases that is not always true.

We could be over-diagnosing and over-treating certain diseases. Whether it’s imaging, urology, radiation oncology, or oncology, it really is a team effort because we all bring something unique to the table. We really need to work together to make sure we come up with the best plan and the best answers.

Join us to read the rest of Dr. Koo’s comments on imaging recurrent prostate cancer.