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Conversations With Prostate Cancer Experts


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NRG Oncology’s Clinical Trials

Dr. Mark Hurwitz, a widely recognized leader in the fields of thermal medicine and genitourinary oncology, is the Vice-Chair for Quality, Safety and Performance Excellence and Director of Thermal Oncology for the Department of Radiation Oncology at The Sidney Kimmel Medical College at Thomas Jefferson University in Philadelphia, Pennsylvania.

Dr. Hurwitz talked to Prostatepedia about NRG Oncology and a trial he’s running with them that looks at anti-androgen therapy and radiation therapy with or without Taxotere (docetaxel) in treating patients with prostate cancer that has been removed by surgery.

Why did you become a doctor?

Dr. Hurwitz: Medicine is an extraordinarily rewarding career in regards to being able to help people at important and often critical junctures in their lives. It’s extremely humbling to see strangers walk into my office and put their trust in me to help them through a difficult time in their lives.

It’s an enormous responsibility.

Dr. Hurwitz: It is, but one that comes with many years of training and preparation for a physician to get to the point when we enter practice.

What is NRG Oncology? What has been your involvement with the group?

Dr. Hurwitz: Several years ago, the National Cancer Institute (NCI) mandated the merging of cooperative cancer research groups into fewer but larger groups. One of these groups NRG Oncology, was the result of the merging of the Radiation Therapy Oncology Group (RTOG) with the Gynecologic Oncology Group and the National Surgical Adjuvant Breast and Bowel Project (NSABBP). This dynamic new large cooperative research group is primarily supported by the NCI. It’s been exciting and rewarding to be a part of this new larger group putting all our resources together to bring trials to patients.

I’ve been involved with NRG Oncology since its inception. Predating that, I was involved with both RTOG, as well as the Cancer and Leukemia Group B (CALGB) during my years at Harvard Medical School.

What kinds of trials does NRG oncology run?

Dr. Hurwitz: The focus of cooperative groups, including NRG Oncology, is on conduction of clinical trials to answer important questions that are best addressed by getting multiple centers involved. These tend to be Phase II or Phase III trials involving hundreds, and sometimes thousands of patients, to answer a critical question that experts in a given field see as being one of the most impactful issues to address for a given set of patients.

NRG is also involved in translational science as well. Almost all of our clinical trials have an incorporated translational aspect to them to answer leading-edge questions in regards to some of the pertinent science behind advancing treatment for our patients.

Are the participating institutions limited to within the US?

Dr. Hurwitz: There are international participants. The group does have a North American focus. Therefore, the United States, as well as many Canadian institutions, are very active in NRG, but NRG has branched out to include international institutions outside of North America as well.

Is it difficult to enroll patients in trials?

Dr. Hurwitz: We all in academic medicine seek to engage more patients with involvement in clinical trials. Only a small percentage of patients nationally participate in clinical trials, so there’s a real opportunity to match patients and their needs with the clinical trials that will help advance the field, as well as their own personal care.

Some of the challenges include having appropriate trials available for patients seen within a practice, as well as the time commitment both in terms of the extra time that the physician needs to take to explain trials as well as the resources needed to support the conduction of clinical trials at a given site.

There is also the issue of awareness both on the patient and provider sides as to opportunities for clinical trial participation.

Why should patients consider joining the clinical trial?

Dr. Hurwitz: There are several reasons for patients to consider trials. A trial often provides patients access to leading-edge therapeutic strategies that may not be available off clinical trials.

It also will help provide additional information that will benefit future patients, although our focus is always on the patient who is sitting in front of us.

Also, interestingly enough, there are multiple studies that have looked at the impact of clinical trial participation on patient outcomes, with very consistent findings that patients on clinical trials tend to have better outcomes including survival outcomes than patients not on clinical trials. This is likely due to a number of factors, including the rigorous monitoring of patients on clinical trials as well the follow up after treatment that is done. These patients are followed very closely. There are state-of-the-art treatment guidelines that must be followed on clinical trials to help reduce undesirable variability in patient care. These aspects of clinical trials help to improve outcomes regardless of the particulars of any clinical trial.

Are there certain stages along the cancer journey when a patient should consider a trial?

Dr. Hurwitz: There are clinical trials that are suitable for patients across the whole spectrum of disease severity. In the case of prostate cancer, there are trials for patients with very favorable risk disease for which active surveillance is an option to trials for patients who are on second or third line interventions for metastatic prostate cancer. And everything in between. It’s not a matter of whether a patient has a certain stage of disease. There are questions to be answered at each stage of a given disease for which clinical trials may provide benefit.

Are there any considerations patients should keep in mind as they evaluate trials?

Dr. Hurwitz: People have to gauge the particulars of a trial much like the particulars of any proposed treatment for malignancy in regards to what makes them most or least comfortable with the options before them.

Let’s say a patient participates in an NRG trial. Are they informed of the results once the trial is completed?

Dr. Hurwitz: There have been increased efforts in recent years to disseminate outcomes of trials to patients. It’s a particular challenge in some diseases like prostate cancer where the results may come a decade or more after trial participation.

That’s true.

Dr. Hurwitz: There is an effort regardless of the outcome of the trial to make not just practitioners but patients aware of the results.

Are there interesting NRG prostate cancer clinical trials that you’d like to highlight?

Dr. Hurwitz: I’m happy to highlight NRG-GU002, for which I am privileged to serve as the principle investigator. This trial builds on a prior Phase II single-arm RTOG trial, RTOG-0621, which I led that revealed very promising outcomes with the addition of Taxotere (docetaxel) and hormonal therapy to radiation for patients with adverse risk factors post-prostatectomy. NRG-GU002 builds upon the single-arm Phase II trial as a randomized Phase II into Phase III trial exploring the use of radiation and hormonal therapy with or without Taxotere (docetaxel) in men who fail to achieve a PSA nadir of less than 0.2 nanograms per milliliter after prostatectomy. This is a particularly high-risk group of patients in regards to risk of subsequent treatment failure. We have been very encouraged by the efficacy of Taxotere (docetaxel) in treating prostate cancer. Taxotere (docetaxel) has been shown initially in metastatic prostate cancer and subsequently in locally advanced disease to have a survival advantage—as opposed to using radiation or hormonal therapy alone in the primary treatment setting. Therefore, there is a lot of interest in exploring its utility in the post-prostatectomy setting for high-risk patients.

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Focal Therapy For Prostate Cancer: A Urologist’s View

Dr. Edward Schaeffer is the chair of the departments of Urology at Northwestern University Feinberg School of Medicine and Northwestern Memorial Hospital.

Prostatepedia spoke with him about focal therapy for prostate cancer.

Why did you become a doctor?

Dr. Schaeffer: I’ve always been fascinated with how things work. My fascination dates back to when I was a child who loved to understand the mechanisms that made an alarm clock work. Over time, that interest in the mechanical nature of things evolved to an interest in the complexities of animals and living things. From there, I got intrigued by not just normal anatomy and physiology, but also by understanding how and why things break down. Restoring things to normal is one appealing part of medicine.

If you can understand why things fall apart, you can understand how to fix them. That is the essence of part of medicine. The other part of medicine is humanism, the ability to help people. It’s truly such an honor to help people with their problems. I’m reminded of that privilege daily.

Have any particular patients over the years stood out in your mind? Any cases that may have changed how you view the art of medicine?

Dr. Schaeffer: I have an open style with my patients, and they can all reach me through my personal cellphone number. I give them my personal number because I view my position in their lives as a privileged one.

Patients come to me with a problem, and they really open up to me about their own health problems, their anxiety and fear, and the psychological impact that their new disease diagnosis has had on their life. Because they’ve been so open with me, I view it as part of my role as a physician to give them access to me if they need me.

I’ve developed personal and close relationships with all of my patients. I maintain objectivity, but the disease I take care of is a personal one. It’s a cancer, and there can be a lot of emotional burdens that go with it. My patients are always changing my view of my role in medicine and my role in life and family. I’ve learned so much from them.

That’s fairly unusual to provide your own cellphone number, isn’t it?

Dr. Schaeffer: It’s highly unusual! But I’ve never done anything based on what other people do. I just do what I think is right.

What is focal therapy, and where does it fit into the spectrum of treatments that are available to men with prostate cancer today?

Dr. Schaeffer: Focal therapy is one type of interventional treatment for men who have localized prostate cancer and for men who have localized prostate cancer that is contained within the particular focused area of the prostate.

Generally speaking, when patients have a low-volume, low-grade prostate cancer, the first go-to option is typically a program of surveillance because we often deem these as cancers that don’t require any active intervention. But some patients want to do something or don’t want to have treatment of their entire prostate, and so they may request that we focally ablate the suspicious or concerning area. That is a potential option.

When we do focal therapy, we always have to follow the patient and monitor not only the area we treated but also the other areas of the prostate for cancers that may crop up.

In some ways, it’s more intensive active surveillance because it’s active surveillance plus something. On the spectrum, it’s a minimalist approach, but the jury is still out as to whether it’s an effective approach. While there are many anecdotes out there where people have thought it’s been successful, it hasn’t been widely studied.

Is that one of the controversies around focal therapy?

Dr. Schaeffer: Yes, I would say so. It has not been rigorously studied with one exception. One type of focal therapy, photodynamic therapy, has been studied in a prospective clinical trial. This trial was promising: it showed that focal therapy can reduce the amount of cancer and reduce the progression of cancer.

Are the side effects fewer with focal therapy than with whole-gland therapy?

Dr. Schaeffer: That is the idea of it. That is correct.

Let’s say someone gets focal therapy and then their cancer recurs. Does the previous focal therapy impact or impede their ability to get another primary therapy like radical prostatectomy or radiation?

Dr. Schaeffer: It makes it more potentially challenging to do what we would then call definitive secondary or salvage treatment, but that’s not true for every patient all the time. When somebody has prostate cancer in one area of the prostate and undergoes focal therapy, they’re monitored for two things.

One is recurrence or regrowth of the cancer locally. Second is the development of additional cancer in another area of the prostate. Individuals who have had focal therapy may require additional treatment for one of two reasons.

One reason may be that the area where the cancer was before was not effectively treated the first time. That would be disease persistence. Then the other reason may be that perhaps a cancer developed in another region of the prostate. We know that prostate cancer is a multi-focal disease, so it certainly is possible that a cancer could occur somewhere else. That is why people who have had focal therapy can’t give up monitoring their cancer over time.

Any other controversies over the role of focal therapy?

Dr. Schaeffer: The main controversy in terms of focal therapy has to do with the fact that many consider focal therapy to be a treatment, that if you can detect the cancer on MRI, for example, you could focally treat the MR-visible area. There is good research from UCLA and other groups that shows that the volume of the cancer that was originally noted on MRI underestimates the true volume of the cancer by two or three times in some cases.

So, what should you treat? Should you treat only the MRI-visible area, or should you treat the MRI-visible area plus a boundary of prostate around it because there’s this possibility that cancer may extend beyond the MRI visibility? That’s a big controversial area because the more broadly you expand your focal treatment area, the more you increase the possibility of having side effects from more extensive treatment.

Do you have any advice for men who are considering focal therapy?

Dr. Schaeffer: For all individuals with a new diagnosis of prostate cancer, they should really seek the advice of an expert. Somebody who’s well-versed in all treatment options for prostate cancer would be very helpful.

I don’t perform focal therapy myself, but I know experts who do. If I believe someone’s a good candidate for it, or if I think that someone’s not a good candidate for focal therapy, but they’re still interested, I’ll refer them to an expert so that my patients can get their advice. I think it’s important that patients seek advice from an expert in the management of prostate cancer who can help them understand the full implications of the treatment options.

Would you encourage most patients to seek a second opinion?

Dr. Schaeffer: I do, unless their diagnosis was at an NCI-designated cancer center or hospital in similar standing. If they’re at a center of excellence already, they don’t have to go to a second one unless you’re uncomfortable with your team. I think that the idea of seeking out somebody with expertise in that particular disease area is very important to get the best advice possible.

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Dr. Hashim U. Ahmed on Today’s Focal Therapy For Prostate Cancer

Dr. Ahmed is Professor and Chair of Urology at London’s Imperial College Healthcare.

His research focuses on prostate diagnosis using novel imaging and tissue biomarkers, prostate treatments that reduce the harms of traditional surgery and radiotherapy, and clinical trials and health technology evaluation.

Prostatepedia spoke with him about the current state of focal therapy for prostate cancer.

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What is focal therapy?

Dr. Ahmed: Focal therapy is about targeting the tumor within the prostate with a margin of normal tissue. The tumor is one that we believe that were we to leave it untreated, would progress, grow and spread, and impact the patient’s life at some point. By doing so, we avoid treating the entire prostate. We avoid damaging as much normal little tissue as possible. By damaging as little tissue as possible, we aim to maintain as much function as possible for that particular man, whilst at the same time treating the cancer that would otherwise cause problems in the future.

What are some of the various forms of focal therapy? Focal therapy is an umbrella term, is it not?

Dr. Ahmed: It is an umbrella term. I often joke that there’s almost like a catwalk of treatments that can be used for focal therapy. The traditional ones were cryotherapy, which freezes the tissue, and high intensity focused ultrasound (HIFU), which uses very focused ultrasound waves that heat up the prostate. You can use laser, which also heats up the prostate. You can use electrocution of the cells, which is called irreversible electroporation. There are now some new injectable drugs. You can inject hormone drugs or molecules that are activated by PSA, which then kill the prostate cells once they are injected into the prostate. There’s a lot of activity going on.

What I often say is that all of these different modalities are interesting. It’s good to see that commercial bodies are really interested in this field. That shows that the concept has real legs and everybody sees this as a big future, so that everybody’s crowding into the market. Ultimately, these are all tools, if you like— surgical instruments for me to do my focal therapy. No one tool can be applied to all tumors.

Let me take an example. If you had a big prostate with a tumor high up in the gland, there’s no way HIFU would be able to reach it. The ultrasound wave just can’t get that far. Even if it could, by the time it reached the tumor, there would be so much tissue it went through that it would lose its energy. For that particular tumor, an anterior tumor, something like cryotherapy is probably going to be better for that particular man than HIFU. A posterior tumor near the rectum, but contained in the prostate, probably does really well from HIFU at the moment, but could easily be treated in the future using these injectable drugs, if they’re to be efficacious.

Which form of focal therapy is best really does depend on where the tumor is, how big it is, and how big the man’s prostate is. Are there other characteristics within the prostate, for instance, like calcification, which means you can’t see the tumor? Those calcifications might, potentially, deflect the energy. There are a lot of other considerations, but there are quite a lot of things that you can use. I would say the two that are in pole position at the moment, just because they’ve been around for longer and therefore they have a lot of data, and the two that I use routinely in clinical practice, are HIFU and cryotherapy.

For which men is focal therapy usually an appropriate choice?

Dr. Ahmed: Firstly, focal therapy is a choice for the man who wishes to preserve or minimize his risk of genitourinary side effects like incontinence and erectile dysfunction as much as possible. You could argue that everybody wants that, but there are some men who will just have radical treatment and say to me, “I understand that I have side effects, but I just want it sorted out.” There are other men who prioritize minimizing the genitourinary impact that treatments have.

Focal therapy is also a good choice for men who have one index lesion. In other words, they have one tumor that is clinically significant, but at the same time have either no other tumors or one or two clinically insignificant cancers. In those men, we would target the main, biggest, or highest grade tumor because that is the one, studies have shown, that is likely to grow, progress, and metastasize if it was left on its own. The other, smaller, low-risk lesions are the type of indolent disease that a lot of men in the male population have that doesn’t need immediate treatment. You can monitor those after you’ve knocked out the main tumor, for instance.

You wouldn’t want to just knock out those one or two insignificant cancers while you were in there anyway because of potential side effects?

Dr. Ahmed: One of the reasons is it’s difficult to localize one or two millimeters of low-risk disease. In order to treat those, you’d have to end up treating a block of tissue. By the time you’d treated that block of tissue, or two other blocks of tissue, you’re probably at 70 to 80% of the prostate volume.

And if you do that, you might as well just target the whole thing?

Dr. Ahmed: You might as well just treat the whole thing because you’re going to cause as much damage. These small lesions are often not visible on MRI. They’re found on random, systematic biopsies, and you have no idea exactly where they are.

Another consideration is the characteristics of the lesion itself that we would want to treat. It could be one of two things: intermediate Gleason Grade 7, so 3+4 or 4+3. Or, there’s an increasing recognition that high volume Gleason Grade 6 is also something that is better treated immediately than monitored because that is also likely to progress.

For unfavorable, if you like, low-risk disease and intermediate-risk disease where there is one index lesion you can carry out focal therapy. If you can have intermediate-risk disease, which has two or three significant lesions, you would be better served having radical therapy.

What happens if a man gets focal therapy and later his cancer recurs? Can he go on to other subsequent treatments?

Dr. Ahmed: This is quite an important topic now. We know that following focal cryotherapy, focal HIFU, and some of the newer emerging focal therapy modalities that about 15 to 20% of men will either have residual or recurrent disease in the area that’s already been treated. Most of those men will be eligible to have a repeat session of HIFU or cryotherapy. Certainly in my practice, I tell men there is a one in five chance that we may have to repeat the focal therapy to the same area. Almost invariably, all men see that as just part of the intervention. I would argue having two treatments in a fifth of men is probably part of the treatment.

If they fail two treatments in that area, then they really should go on to have radical therapy, or a change in the type of treatment that you give. If the cancer has resisted 80 to 90 degrees centigrade temperature changes twice, or with cryotherapy minus 50/minus 60 degree centigrade twice, then that is an aggressive tumor. It probably has got a very aggressive blood supply and we need to change tacks.

There is a group of men who develop new lesions in untreated tissue. Some of those men can have another focal therapy, but most of them will go on to have radical therapy because their untreated tissue, if you like, has declared itself as unstable. It has a propensity to develop new tumors, and therefore, it would be better to treat the entire prostate.

About 15 to 20% of men over five to six years need a second focal therapy treatment. Overall, about 5 to 7% of men go on to have radical therapy, despite one or two focal therapy sessions. Now that is five to six-year data; we don’t have ten-year data at the moment, either from HIFU or cryotherapy. The newer modalities don’t even have five to six-year data.

Is it safe to say focal therapy is still an emerging option and that we still don’t have all the data?

Dr. Ahmed: I guess it depends on how you define that level of evidence. If we have to wait ten to fifteen years, then yes. If you argue that we’ve now got good five to ten-year data showing non-inferior cancer control, superior toxicity, or superior side effect profiles after focal therapy, then there are a considerable group of men who will accept the uncertainty of the lack of ten to fifteen-year data. They prioritize genitourinary function and they are not compromising their cancer control, at least at five to six-years median follow-up. And they can still have surgery or radiotherapy afterwards.

In the United Kingdom, in certain centers, focal therapy has been offered side by side with other radical therapies within the National Health Service, as part of the NICE, or National Institute for Clinical and Healthcare Excellence, approvals that we have.

What are some of the other controversies over focal therapy?

Dr. Ahmed: There are a number of controversies. One big controversy is this lack of ten to fifteen-year data. I was in the European Congress a couple of days ago. There was a Pro/Con focal therapy argument. I was pro and the person before me was con. He stood up and said, “We don’t have fifteen to twenty year data.” Five years ago, we didn’t have five-year data. A couple of years ago, it was you don’t have ten-year data. When we first started, they said well you don’t have any one year data on biopsies. This is the first time I’ve heard people stand up and say, well you don’t have fifteen to twenty-year data. It’s slightly amusing. It’s infuriating, as well, because the goalposts keep on changing. The long-term data will come; we’re collecting all the data in registries in the United States, the United Kingdom, and European centers. It’s all very robust data collection. We’re doing trials to see if men will accept randomization between radical and focal therapies. Those trials are tough. Men generally want to choose their therapy rather than allowing themselves to be randomized, but we’ll see.

Then the other controversies are around the areas that we touched on. What happens to the untreated tissue? So far, about 4 to 5% of men over the five to six years of median follow-up that we have in our series of several hundred cases have developed new lesions in untreated tissue. Now, those are probably just tiny bits of Gleason 7 tumors that the biopsy and MRI missed that then subsequently progressed. Some of them will be new lesions, but some of them will be disease that was missed in the first place, which declare themselves later. By ten years, it might be higher. So far it’s quite low.

One of the arguments against focal therapy is that this is a multi-focal disease. The untreated tissue is just going to show up with lots and lots of cancers, but that has not been the case, so that has been quite reassuring. The other controversy is around the point that MRI is not good enough and biopsy is not good enough. But I think both MRI and targeted biopsy are good enough. You can never be 100% in anything. If you look at breast mammography, the data shows that a negative mammogram can miss anywhere between 5 to 30% of breast cancers, yet we still use it as a screening tool. We all accept that nothing in medicine is certain. Then there’s concern about what happens to men who fail focal therapy. Can we remove the prostate, or are these men too scarred. What happens in terms of their cancer control? It’s early days yet, but certainly technically, removing a prostate after focal therapy is easier than removing a prostate after failed radiotherapy. It certainly is more scarred around the treated area, though. Does that mean men shouldn’t have focal therapy?

I would argue not because we’re giving radiotherapy to hundreds of thousands of men. It’s an accepted treatment modality, and if it does fail, it’s tough surgery afterwards. That is, unfortunately, the nature of the beast. When the first treatment fails, secondary treatments are always going to be a little bit more difficult, if not a lot more difficult.

It is difficult to perform that second surgery or men will have more side effects after their surgery?

Dr. Ahmed: The concern is both. If it’s more difficult to perform, then are they likely to suffer more side effects? And, as a result of the surgery being difficult, are we going to get more positive margins? Are they going to fail more often?

These are men whose tumors are going to be very aggressive by nature because, as I said, they resisted extremes of temperature, sometimes twice, and there are still a few cells. So they’re going to be pretty aggressive. The failure rates might be higher in that group, just because of the focal therapy paradigm. Just like radiotherapy, when you get radio-resistant cancers they are generally more aggressive and nastier cancers just by natural selection, if you like.

Do you have any advice for men who are considering focal therapy?

Dr. Ahmed: It’s very important when you are first diagnosed with prostate cancer not to rush into treatment. It’s important to do as much reading as you can and have consultations with urologists and radiation oncologists. If you haven’t been told about focal therapy, ask whether you’re suitable. You might get an answer that says, “Well, it’s not proven.” But if you are keen to explore it, you should definitely have a consultation with somebody who does focal therapy so that they can tell you first whether you are suitable, and secondly, what the outcomes might be in your case. I think every good focal therapist will share the uncertainties, as well as the certainties, around the treatment that they give.

If they’re not sharing those uncertainties, then see somebody else. It’s also very important that they quote their own data. That data, ideally, should be published in the public domain because that is a sign, first of all, that you’re being told the right outcomes for that surgeon or physician. Also, it’s a sign that physician takes their trade seriously and is constantly looking to see how they can improve, as well as sharing their data with their peers.

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Focal Therapy

In April, we’re talking about focal therapies.

Dr. Snuffy Myers comments:

“Interest in focal therapy is fueled by the promise of cancer control with fewer side effects than are seen after radiation or radical prostatectomy. From the patient perspective, this is certainly an attractive option. As a result, we have seen the development of an increasing list of approaches to focal therapy.

There are a number of issues that make critical evaluation of the various focal therapies problematic. First, with the exception of a recent trial that involved laser, randomized clinical trials are absent. There is even a controversy about what is the best control group. The laser trial just mentioned used an active surveillance control group. The second approach would be to randomize against surgery or radiation therapy. The major problem is that such trials have proved nearly impossible to run because of poor accrual. For this reason, I suspect that focal therapies are most likely to find a clinical niche as an alternative or add-on to active surveillance.

Another issue is that we lack trials that randomize between two different focal therapies, so it is difficult to know what approach to recommend for a given patient.

For example, cryosurgery and high intensity focused ultrasound (HIFU) have both been around for many years and have never been directly compared in a clinical trial. In developing focal therapies, it is currently common practice to treat a group of patients with a new technology and then follow those patients over time. Results are reported after 1, 5, and 10 year follow-ups and comparisons made to historical results with radiation or radical prostatectomy.

However, we have long known that such comparisons with historical data are often unreliable. As mentioned above, a better, more time efficient approach would be to test focal therapies as an alternate or add on to active surveillance rather than as an alternate to radical prostatectomy or radiation.”

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Dr. Daniel George on PSA Recurrence

Dr. Daniel James George is Professor of Medicine and Professor in Surgery at Duke University.

Prostatepedia spoke with him recently about biochemically recurrent prostate cancer.

Have you had any patients whose cases have changed either how you view your own role as a doctor or how you view the art of medicine?

Dr. Daniel George: As we evolve new therapies and indications for treatment, it’s really interesting how that affects our relationships with patients. As an oncologist, my relationships with patients have become more longitudinal. What I mean by that is: people are living longer than ever. I’m beginning to recognize my treatments in the context of not just the short-term endpoint of how to control my patient’s disease in the next few months but in terms of the ramifications for his life and long-term survival. What does it mean in terms of his functional well-being, not simply now, but in a year from now or five to ten years from now?

In many ways, it comforts patients to hear the perspective, that I see them as a long-term survivor, and that I’m thinking about the implications of our treatments in a long-term perspective. That helps the patient invest in his own life and well-being for the long-term, whether that be diet, exercise, sleep, or all these other behavioral interventions that can really impact their quality of life.

You’re basically saying that prostate cancer is becoming more of a chronic disease.

Dr. George: It has been for some patients, and we’re beginning to recognize it more and more for all patients.

We used to think of short-term goals for some of our most advanced cases of prostate cancer—just in terms of disease control or palliation and not worry about the long-term implications of treatment. While on the other end of the spectrum we would have cases where we don’t have to treat the disease at all or maybe treat it minimally in others. Now I’m recognizing prostate cancer as a chronic disease for everybody, and so everybody needs to think of the long-term implications of treatments.

Likewise, we need to think of the implications of our sequential therapies and their cumulative side effects.

Can you define M0 prostate cancer, or biochemically recurrent prostate cancer, for patients?

Dr. George: This is probably confusing because of its name. We refer to prostate cancer in terms of stage. Stage refers to the extent of the disease. The Gleason Score or grade refers to how it looks under the microscope, its aggressiveness. But stage refers to the progression of this disease. Do they have bone metastases? Do they have distant lymph node metastases or other sites of disease? Or is it localized?

We usually use three categories: the T stage, which is the localized tumor, the N stage, which is the lymph node status, and then the M stage, which is the presence of metastases that are distant from the prostate. M0 refers to patients who have no distant metastasis. Think of M0 in terms of patients who are newly diagnosed with prostate cancer.

Recurrent prostate cancer patients are those who’ve had local therapy, surgery, or radiation, and who now have evidence of disease recurrence by PSA. After these treatments, we know that your PSA should be 0 or very low, and it should stay low. If your PSA rises and continues to rise, that’s an indication of disease recurrence. Yet, in many cases, they’re what we call M0 because, when we stage the patient with a bone scan or a CT scan, we can’t see any evidence of cancer. Many of those patients have what we might otherwise refer to as microscopic metastatic disease, disease that’s just below the level of detection. Some of them could have local recurrence or recurrence just within the pelvis and regional nodes that’s not distant. We now know from recent studies that the majority of those patients are going to relapse with distant metastatic disease. In other words, they have distant metastatic disease, but it’s just below the level of detection.

So, this is a bit of a misnomer because we’re treating them with systemic whole-body treatment therapy now because we recognize the risk of distant metastatic disease for the majority of these patients. We’re beginning to use newer imagining techniques, such as PET scans, that could be more sensitive at picking up this microscopic metastatic disease. That shouldn’t deter us from applying the current data to that patient population.

I think of M0 prostate cancer as being low-volume castrate resistant prostate cancer. When we think of it that way, it makes sense that the drugs we’re using work and work even better in that low-volume population. We should use them because M0 is just an early continuation of that metastatic process.

What are these systemic approaches that patients are likely to receive? What are the implications down the line in terms of side effects, and in terms of the longer longitudinal quality of life issues you mentioned earlier?

Dr. George: This is an important aspect of the care for these patients because we have two studies—and a third will soon be reported—that demonstrate a clinical benefit from using what we have broadly termed secondary hormonal therapies, therapies that we add to primary androgen deprivation (ADT) or testosterone suppression.

Patients for whom testosterone suppression has failed can respond to another hormonal intervention later. These are drugs that target the androgen receptor, the protein that testosterone binds to, and inhibits it from signaling. It shuts off what seems to be the most common mechanism for resistance to testicular testosterone suppression. That is an overexpression or overabundance of this receptor, which makes prostate cancer cells sensitive to low levels of residual testosterone in the body.

Xtandi (enzalutamide) and Erleada (apalutamide), in two separate Phase III studies, have demonstrated a clinically significant benefit: a delay in the time to metastasis. The FDA has accepted this as a meaningful endpoint because of the degree of delay. It was associated with about a two-year delay in the time to metastasis in this population.

Patients who were at high risk for developing metastatic disease were in the control arm and developing metastatic disease within about a year of coming on the study for the placebo arm. For the treatment arms, with Xtandi (enzalutamide) or Erleada (apalutamide), we’re seeing a delay of about two additional years. That means three years until the time of metastasis.

The results suggest that we’ve changed the progression of this disease dramatically. In addition, both studies showed a strong trend in favor of the treatment arm for improved overall survival associated with this delay in metastasis. Even though the data may not be as complete because it takes a longer time to report, we’re seeing this correlation in metastasis-free survival, if you will.

Again, I caution the semantics here because these patients do have metastases; they just can’t be seen yet. But the delay in that radiographic appearance of metastasis is associated with an improved survival.

What’s the approach to finding smaller metastases earlier on with the newer imaging techniques? And if they are very small, do you treat them aggressively with radiation, do you continue using the systemic therapies, or do you use a combination?

Dr. George: There is a mix of presentations of patients. When we image with a novel PET-imaging tracer, we’re going to see more than one site of disease in most patients. We’re going to see multiple lymph nodes, multiple bone metastases, or maybe lymph and bone metastases.

For a subset of about 20 percent of patients, we see this disease limited to only lymph node disease or only one or two bone metastases. We refer to this as oligometastatic disease, which we have yet to biologically define. Clinically, we know that it’s associated with a longer survival.

Oligometastatic prostate cancer raises the question of whether or not these patients could be managed with therapy localized to those sites, therapy that does not necessarily expose them to further systemic therapy. We don’t have a lot of data in the castrate-resistant setting, but in the hormone-naïve setting, there are some data that suggest that there can be a delay in the time to initiating subsequent hormonal therapy by doing that.

There’s a study out of Europe, but the median effect was relatively small, just a few months. It’s not clear that this is going to be a meaningful difference for most patients, but it is something that can be discussed.

A lot of those treatment approaches can be done with minimal intervention, external radiation, ablations, or limited surgery. Those will be options. But in the majority of these patients that we do this molecular imaging for, we’re going to find evidence of more than one site of disease or multiple lesions. This suggests that they need a systemic therapy approach.

It’s reasonable to extrapolate this data because we know from the placebo arm of these studies that these patients went on to develop metastases in their bone scan or CT scan within months, 50 percent of them within a year, and many of them in just a few months of their subsequent scan. The likelihood is, if we’d done the molecular imaging at baseline on these patients,we would have seen it. Yet still, in this population, we’re seeing a treatment effect.

We see the treatment effect regardless of what level of PSA doubling time you have. In patients who have a PSA doubling time of just two or three months, we see a dramatic treatment effect. In patients who have a doubling effect of eight or ten months, we still see a dramatic treatment effect in terms of prolongation in the time to metastasis—fewer events in those cases, but still, we see that treatment effect.

The PSA doubling time is an important parameter that we’re using now, in addition to these imaging stats, to determine who we should treat with these drugs and their prognosis.

Isn’t doubling time an indication of the aggressiveness of the disease?

Dr. George: It is. We knew this earlier in disease prior to hormones. PSA doubling time was very prognostic for time to metastasis and overall survival. It’s been less studied in the castrate-resistant setting, when patients have progressed on primary hormonal therapy, but we’re still seeing it there. In fact, the results are really dramatic.

There were some abstracts at the Genitourinary Cancer Symposium (GU ASCO) around this data. There have been reports from these two Phase III studies with Xtandi (enzalutamide) and Erleada (apalutamide) that demonstrate this. We believe there is a strong correlation between a shorter PSA doubling time—a shorter time to bone metastasis—and shorter overall survival.

Just to put these studies into context, the requirements were that PSA doubling times were less than ten months. If doubling time is a year or longer, these are slow-growing cancers. Even though they’re castrate-resistant, these are patients who will live for many years with no metastasis, so it’s reasonable just to observe their disease. For the studies, the median or 50th percentile PSA doubling time was around four months. That’s really short and aggressive.

That’s why we saw that the average time to metastasis was just about a year in the control arms. It’s important to recognize where your patient is in this continuum because it guides whether we should treat him like we did on the study, or if their disease is too slow growing to justify the treatment.

What other considerations are important for patients who fall into this category?

Dr. George: The important thing for patients to know: not to worry. I know that as a physician, it’s easy to say ‘don’t worry about your rising PSA level,’ but as a patient, it is hard to ignore.

Join us to read the rest of Dr. George’s comments about biochemically recurrent prostate cancer.


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Dr. Maha Hussain On Biochemical Recurrence

Dr. Maha Hussain is the Genevieve Teuton Professor of Medicine in the Division of Hematology, Department of Medicine, and the Deputy Director of the Robert H. Lurie Comprehensive Cancer Center of the Northwestern University Feinberg School of Medicine.

Prostatepedia spoke with her recently about biochemically recurrent prostate cancer.

What is biochemical recurrence?

Dr. Hussain: A biochemical recurrence implies that an individual with prostate cancer who has received therapy now has evidence of disease activity as reflected by their PSA blood test. In the context of negative imaging, the PSA is a flag. It generally indicates a relapse. Generally speaking, when the patient has a rising PSA, they get imaged. If the scans are negative, then this becomes purely biochemical recurrence.

Why is this a disease state that we’re particularly focused on? What are some of the key issues in how we approach treating these men?

Dr. Hussain: There are two settings of biochemical recurrence. One is the non-metastatic hormone sensitive setting. This means a patient has had local therapy with surgery and their prostate was taken out, or they’ve had radiation therapy with or without hormonal treatment, and now they have a PSA that’s going up. This implies there is cancer activity. Generally, imaging is done, and most of the time, conventional imaging such as bone and CAT scan are negative.

While not imminently harmful, non-metastatic hormone sensitive biochemical recurrence has significant psychological implications for the patient because it reminds them that there is cancer activity in their body that’s growing.

With regard to management, salvage radiation plus hormone therapy is the standard of care for patients who developed PSA-only relapse post radical prostatectomy as it reduces risk of mets and improves longevity. While there are options for patients who had radiation therapy plus hormonal therapy, they are not optimal.

For example, while hormone therapy is an option for patients whose PSA started to increase after salvage radiation and hormonal therapy, the totality of the data to date does not suggest significant benefit for early hormone therapy versus waiting until there’s a reason to treat.

This population; non-metastatic hormone sensitive PSA relapse, tends to live quite long, and some may not develop visible mets. The speed by which the PSA starts to go up and how fast it increases—what we call doubling time—can imply earlier versus later development of metastatic disease. Detailed discussion is needed to address options, pros and cons of treatment, and potential options for clinical trials.

The other setting of biochemical recurrence is the non-metastatic but castrate-resistant setting, which differs from the previous setting in that patients were treated with hormone therapy and now their PSA is rising while on therapy; that is the rising PSA is occurring despite the fact that hormone therapy has lowered their testosterone levels to the castration range. This is a different clinical phase of disease where the cancer has shown that it is no longer responsive biologically to the hormonal therapy that they are receiving. We know that, given enough time, cancer will show up. We know also that the speed by which the cancer is growing, as reflected by the PSA rate of increase, has an implication as to how soon the cancer will show up on the scans.

This is an area of an unmet need for decades, until last year when two drugs were FDA-approved for this particular patient population, specifically Erleada (apalutamide) and Xtandi (enzalutamide) based on significantly delaying time to development of metastasis. At this year’s American Society of Clinical Oncology GU (ASCO GU) conference, there was also positive data from another trial with Darolutamide in this disease setting. I believe the drug is in front of the FDA at this moment for review.

These three trials were done in a population of patients who had a worse prognosis as reflected by their fast PSA doubling time—a doubling time of 10 months or less. This is because these patients are likely to show metastases within an average of about two to two and a half years.

The issue is whether there is benefit for people who don’t have that kind of PSA doubling time. What if the doubling time is one or two years? It certainly is an area where we need to think about value to that patient.

For both Erleada (apalutamide) and Xtandi (enzalutamide), the FDA approval did not specify the doubling time requirement. The FDA approved it in all patients who have non-metastatic castrate-resistant disease. Clearly one size does not fit all. It’s critical to make shared decisions between the patient and the treating physician with regard to the value of the treatment, the risks from the cancer, the risks from the treatment, the treatment objectives, and when to initiate therapy.

Some good news about this disease phase is, because it’s invisible cancer, and while this means there’s micrometastatic disease, the patient has some time to think about things and also monitor carefully.

In my experience, probably about 8 to 9 out of 10 patients elect to be on treatment because of the concern over worsening disease and the value based on the clinical trials. There are some patients who feel great, and if they’re not going to have an issue tomorrow, then they want to wait a few months before deciding on treatment. That’s perfectly reasonable.

Isn’t that true for a variety of situations in prostate cancer, that you have time to gather a variety of opinions?

Dr. Hussain: Correct in general, but specially for this disease space because no one is going to die overnight from a PSA that’s not controlled. That’s to put it bluntly. There is that room. Patients should talk with their physician about that and discuss risk-benefit ratios as all therapies have side effects.

For certain patients, those side effects might be more important, especially for those who have significant cardiovascular disease. It becomes important to incorporate risk-benefit and close monitoring, but it doesn’t mean that no treatment should ever be done.

Do you have any other advice for men in this situation?

Dr. Hussain: One thing to remember for men with hormone-sensitive biochemical recurrence who have had salvage therapy or post radiation and hormonal therapy is that if therapy is to be done, it ought to have a good reason. Lowering the PSA alone is not the objective; clinical benefit should be the objective.

There is potential harm from treatment in the absence of proof that giving hormone therapy for a PSA of let’s say 0.5 or 0.6 will have a benefit. One has to balance the risks from the treatment and both physical and monetary risks to the patient and ultimately implement a shared decision.

These conversations with patients can be long and potentially stressful to the patient. Yes, hormone therapy can be given. The issue is not whether it can be given but whether it should be given, and if so, when.

There’s a fair amount of population-based data that suggests there’s no clear advantage, but there’s limited prospective clinical trial data. I would encourage patients to discuss these issues with their physicians, understand the upsides and downsides, and also discuss opportunities for clinical trials. Clinical trials are one space in which we need informative data and partnerships with patients to come up with better answers.

For patients who had radical prostatectomy (surgical removal of the prostate), and then their PSA is going up, their best treatment option is salvage therapy, which involves radiation with hormonal treatment.

Based on the more recent data from Radiation Therapy Oncology Group (RTOG), the radiation involves the prostate bed and the pelvis to include the pelvic lymph nodes with four to six months of hormone treatment. This is something that should be discussed with the care team. Radiation alone is not enough, and certainly the data indicate the combination is better with regard to outcomes. If the patient doesn’t want to do the hormones, that’s fine, but the hormones can reduce risk of progression and potentially add to overall survival.

The other side would be situations where patients have had radiation therapy and have received hormonal treatment as part of their primary treatment. Then they stopped the therapy, and now months or years later, the PSA is rising. That’s a different scenario. The issue is whether to resume hormone therapy or not. That’s when a careful conversation is necessary between patients and their physician because there is no compelling data that say it’s necessary to do the hormone therapy.

So, there are a variety of situations.

Dr. Hussain: Yes and/or access to clinical trials. We know the phases of prostate cancer now. The same disease state now has multiple phases, and it’s becoming complicated. That’s important because this speaks to the importance of personalizing care for the patient at all levels.

We’re becoming more and more personalized about how we categorize the different disease states.

Dr. Hussain: Yes, absolutely, and we do individualize the care. A 50-year-old who comes in with non-metastatic castrate-resistant prostate cancer and no comorbidities has a very different disease than someone who is 85, had a stroke, and is in a wheelchair.

Patients should ask their physicians specifically about the type of biochemical recurrence they have, their expected prognosis based on their PSA doubling time, their risk-benefits ratio, and which scientific information from prospective clinical trials can help guide their decisions. Patients should ask for educational material, and doctors should help patients make a decision that’s not based on being afraid but being informed about the choices, pros, and cons.

Would you give similar recommendations to anyone along any stage of the disease progression?

Dr. Hussain: Absolutely. Informed decisions are critical in every disease setting. But biochemical recurrence is a complicated phase of disease. In the setting of metastatic disease, it’s relatively easy in that there is no question regarding the disease risks. Earlier therapy, before symptoms or before the disease worsens, is better generally. This a disease setting that is likely to cause harm if therapy is delayed significantly.

But with non-metastatic hormone sensitive biochemical relapse, a patient can go for years without having any visible metastasis. It’s more complicated when there’s no imminent danger. At the end of the day, I tell patients with non-metastatic hormone sensitive disease in whom there is no clear data to support benefit from systemic therapy, that this is a gray area where we don’t have compelling data to say that giving hormone treatment is going to give a meaningful benefit. Therefore, one option is we monitor closely with interval PSA checks and periodic imaging. Based on doubling times and trends, what new evidence that comes up, and patient comfort we can watch. Once the patient is informed about the specifics, it is fascinating that the majority tends to be comfortable with watching and about a third are not comfortable with not getting therapy. There is not a one-size-fits-all approach. Personalized shared decision is critical.

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Join A Clinical Trial: Casodex (bicalutamide) + Metformin

Dr. Marijo Bilusic is the director of the National Institutes of Health (NIH) Hematology Oncology Fellowship, and an Associate Research Physician in the Genitourinary Malignancies Branch, Center for Cancer Research,

National Cancer Institute (NCI). He’s keenly interested in tumor immunology and in developing prostate cancer treatments using novel target agents, therapeutic cancer vaccines, antibodies or immune modulations.

Prostatepedia spoke with him about a trial he’s running that looks at men with prostate cancer on Casodex (bicalutamide) with or without metformin.

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Would you walk us through the thinking behind your trial looking at Casodex (bicalutamide) with or without metformin?

Dr. Marijo Bilusic: A former prostate cancer patient of mine had had surgery and his prostate was removed. Then his PSA kept rising, and he was not very keen about hormonal therapy, which was recommended by other oncologists he’d seen before me. I met him, and we talked about what to do. “We’re just going to observe you for now,” I said. “Try to exercise, lose some weight, and make healthy lifestyle changes. We’ll see you back in three months, and we’ll see what your PSA’s doing.”

In three months, he came back, and his PSA was 50 percent less than before. It went from 4 to 2.

I was impressed. I asked him, “What did you do?” “I followed your instructions.” “Lots of people follow my instructions,” I said, “but I’ve never seen anybody have PSA decline just with exercise and diet change. Any other changes from the last time we met?”

“I’ve also been taking metformin,” he said. “I read that metformin can help people with prostate cancer and asked my primary care physician to prescribe it, even though I was not diabetic.” It’s important to note that metformin is not something that we would recommend to prostate cancer patients outside of a clinical trial, yet. That’s why we’re running this study-to learn more about how metformin works and who it may work for.

I was surprised, and grew curious about a potential link. After that, I did a literature review. I found one population based observational cohort study that included around 38,000 men with prostate cancer and diabetes from Ontario, Canada. Authors reported that metformin treatment was associated with decreased prostate cancer mortality: 24% reduction for each additional 6 months of metformin use while use of other anti-diabetic medications did not significantly decrease mortality. This was a very interesting study. Two prospective studies tested metformin in non-diabetic patients with prostate cancer. First enrolled 42 patients with castration resistant prostate cancer who were treated with metformin, 1,000 mg twice daily. Two patients had ≥ 50% PSA decline and in 23 patients (52.3%) had a prolongation of PSA doubling time. Another study enrolled 24 men with newly diagnosed prostate cancer that were treated 500 mg of metformin three times a day before the surgery (neoadjuvant treatment). Metformin reduced

Ki67 proliferation index by 29%, compared to the baseline biopsy, meaning that the cancer became less aggressive with metformin use of about four weeks. That was very interesting.

Nobody knows how metformin works, exactly. Some studies have shown metformin also could help patients with breast cancer and pancreatic cancer, and also observational studies have shown decreased risk of the incidence of cancer, suggesting that metformin can help prevent cancer.

Though we are still trying to understand how metformin works, we do know it’s inexpensive and it’s very safe. Instead of having a treatment of prostate cancer that costs more than $100,000, it would be great to have one that costs only a couple of dollars. We’re not there yet, but we’re hopeful that this trial and others like it will help us continue to learn more about how to best treat prostate cancer.

To learn more about when metformin may work, we came up with the study design to test metformin in combination with Casodex (bicalutamide), an FDA-approved agent for prostate cancer. We selected Casodex (bicalutamide) because testing of this combination using animal model showed the synergistic effect of Casodex (bicalutamide) and metformin. The side effects profile is much better than from Lupron (leuprolide), so we thought that would be a reasonable alternative for people who have biochemically recurrent prostate cancer with rapidly rising PSA.

What can patients expect to happen in the trial?

Dr. Bilusic: First, we have to make sure they’re eligible. When they contact us, we determine if they have a biochemical recurrence, which we define as somebody who’s had prostatectomy followed by two rising PSAs above 0.2. If PSA doubling time is between three and nine months, those patients are potentially eligible for this trial.

We are also looking for people who are not diabetic, but they should have a BMI of 25 or more because the mice models we tested were obese, and one of the side effects of metformin is weight loss. We did not want to give somebody who is skinny to start with a drug that makes them lose weight. Eligible participants should also not have their testosterone suppressed by hormonal therapy. We don’t allow prior hormonal therapy, unless it was given during the primary treatment as an adjuvant or neoadjuvant therapy.

Those are the main inclusion criteria: BMI more than 25, no history of diabetes (hemoglobin A1C should be less than 6.5), testosterone more than 150, no prior hormonal therapy, and PSA doubling time is three to nine months. Then we’ll do a CAT scan and bone scan to confirm they don’t have metastatic disease.

Once we determine they are eligible, we randomize them to one of the two groups. One group (control arm) will receive observation for two months, followed by Casodex (bicalutamide) alone for 6 more months. The other group will receive metformin alone for two months, followed by a combination of metformin and Casodex (bicalutamide) for 6 months. Because Casodex (bicalutamide) doesn’t deprive testosterone, people have normal levels of testosterone, or sometimes higher levels. The total duration of treatment is 8 months or 32 weeks.

They come here to the NIH clinical center once a month, where we do blood work, a doctor evaluation, and we provide medication. During the trial, in addition to regular blood work, we research blood at the start, at the beginning of cycle three, and at the end of the trial. We’re trying to understand the mechanism of how metformin works.

I know that you supply the medication, but are there any fees associated with participating in the trial?

Dr. Bilusic: No, there’s really nothing else for the patient. Everything is provided, and all the care here at the NIH Clinical Center is free. Once a patient is enrolled on one of our protocols, we also support their trip to the NIH Clinical Center, so patients can come from all over the United States. We also provide a stipend for a hotel if they have to stay overnight. And we give them a meal voucher.

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