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Conversations With Prostate Cancer Experts


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The Genomic Revolution Comes To Prostate Cancer

Dr. Oliver Sartor, the Laborde Professor of Cancer Research in the Medicine and Urology Departments of the Tulane School of Medicine, is one of the leading researchers in advanced prostate cancer today. He is also the editor-in-chief of Clinical Genitourinary Cancer and the author of more than 300 scientific papers.

Dr. Sartor puts this month’s conversations about prostate cancer genomics into context for us.

“We can divide genomics into two different categories. The first category is germline genomics, which is the DNA with which you’re born. It’s clear that about 12% of people with advanced prostate cancer will have alterations in their inherited DNA, in particular in genes involved with DNA repair. Most common of these alterations are BRCA2. There are a variety of others that are somewhat prevalent, including ATM, CHEK2, and BRCA1. There are others that are more rare.

The implications of these germline mutations are significant for the patient: in certain configurations they may predispose a cancer to be sensitive to certain therapies, such as PARP inhibitors or platinum-based chemotherapy or (rarely) immunotherapy. There is more complexity, but knowing the germline mutation helps the informed clinician make decisions. In my practice, we test all patients with advanced prostate cancer for these germline mutations. (A National Comprehensive Cancer Network guideline suggests the same approach.)

These germline mutations represent the DNA with which you’re born. That DNA is going to have repercussions if also mutated in your family members. Men who have some of these DNA repair mutations have an increased risk of prostate cancer. In addition, there is a small increased risk of pancreatic cancer and male breast cancer for those with some of the germline mutations. Around 30% of men with BRCA2 will be diagnosed with prostate cancer in their lifetime, but that cancer is more likely to be aggressive if diagnosed. With regards to females, it’s particularly important. Females with DNA repair defects are more likely to have breast and ovarian cancer. Female with DNA repair mutations, in particular BRCA1/

BRCA2, ought to consider having their breasts or ovaries removed at an appropriate time. Prophylactic surgery has been demonstrated to be potentially life-saving for those individuals. The risk of breast cancer may be as high as 70% and the risk of ovarian cancer may be as high as 40%.

Thus, for these germline mutations there are implications for treatment and implications for the patient’s family.

We should be doing prostate cancer screening earlier in men with these DNA repair defects for prostate cancer; we should be doing biopsies at a PSA of 3 or higher, and perhaps even lower, for younger men known to be at risk. Starting screening at age 45 has been suggested by some. In addition to germline genomics, we need to also talk about somatic genomics. Data indicates that about 60% of individuals who have a DNA repair germline mutation are likely to have another second genetic mutation occur within their tumor. In addition, many of the tumors can acquire an alteration in their tumor DNA even when the germline is normal.

Taken together, about 20 to 25% of men may have DNA repair mutations in their tumor’s DNA. That makes them particularly sensitive to certain therapies such as the PARP inhibitors, as I mentioned earlier, or platinum chemotherapy. When you have two DNA repair mutations in the same cell, the likelihood of response to these agents appears fairly high.

There are also other DNA defects of considerable interest, such as alterations of the mismatch repair genes MSH-2 and MSH-6. When these alterations do occur, there is a potentially increased probability of responding to immunotherapy such as the new PD-1 inhibitors.

Overall, the guiding light today in genetics in my practice is to look at both the germline DNA and the tumor DNA. I choose to look at the tumor DNA circulating free DNA (cfDNA) tests, in particular the Guardant Health assay. The ability of other assays to corroborate the Guardant Health findings is not yet clear. There is clear data to indicate that different assays give different results, but nevertheless, I think in the early exploratory phase we’re in now, it’s important to begin to test patients in order to better understand their genomics and hopefully guide us towards better therapies. This will happen part of the time but certainly not all of the time.

There is more to the story of prostate cancer genetics. We’ve looked at androgen receptor mutations that can have implications for a response to Androgen Receptor directed therapy, such as Xtandi (enzalutamide), Zytiga (abiraterone), and Erleada (apalutamide). We’re dissecting a number of permutations that occur. It’s a complex scenario, because very few men have only one mutation. Most have multiple mutations. And in most cases, these mutations are not targetable with current therapies. This is very important for people to know.

Everybody thinks if they get a genomics test that means they’ve got a treatment. It’s not the case. Many times we get the genomics results and find that there are no known treatments we can use for that man’s particular alteration. That said, there is a subset of men who will have informative genomics while many more people will have non-informative genomics.

There is a final issue I’d like to discuss. There is currently a bit of a debate amongst physicians over the utility of PARP inhibitors such as Lynparza (olaparib) as compared to platinum chemotherapy. But it is noteworthy that platinum-based chemotherapies are inexpensive compared to PARP inhibitors. This does not require a clinical trial. (Most men will access PARP inhibitors through a clinical trial, although sometimes insurance companies are willing to try.)

As it turns out, neither the platinum-based chemotherapies nor the PARP inhibitors will be effective forever, so we do need strategies to manage patients after PARP inhibitors or platinum-based chemotherapies fail. Currently, that space is unexplored. We have to gather much more data before we can make conclusions about those with underlying DNA repair defects who have failed platinum-based chemotherapy or PARP inhibitors.

This is an area of active and important investigation that represents a conundrum for many patients today. I’ve got a patient right now going through this. We’re debating what to do next. I’ve tried to be as honest as I can when I say, “I don’t know what to do, but we’ve got to try something.”

We are in the middle of a revolution, but the parts and pieces are not yet clear. For some, understanding tumor genetics at the current level is helpful. For others, it is perplexing and expensive.

Join us to read this month’s conversations about prostate cancer genomics.

(Already a member? You can read all conversations in your copy of April’s Prostatepedia.)


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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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Prostate Cancer Recurrence

Dr. Alicia K. Morgans is a medical oncologist at the Robert H. Lurie Comprehensive Cancer Center of Northwestern University in Chicago, Illinois. She specializes in treating advanced prostate cancer and is particularly interested in addressing treatment side effects.

She frames Prostatepedia’s March conversations about prostate cancer recurrence.

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

One of the most common questions I’m asked as a doctor who treats prostate cancer is: what happens to me if my cancer comes back? This is always a difficult conversation, especially because people often ask it in the presence of their family members. A man’s wife or child is also really interested in knowing the answer to the question. The question is often driven by anxiety and fear in men who have already undergone what can be a life-altering treatment experience. They’re trying to look ahead and plan for their future. But there are many parts to any possible answer.

First: what do you go through to monitor before the cancer comes back? After treatment, we follow a man’s health, watch his PSA intermittently over time, and often do imaging studies.

If the cancer comes back, the first sign is often that a man’s PSA starts to rise. At this point, we typically use imaging studies to understand what the disease is doing. Even when the PSA is really low, our new imaging technologies can show us where the cancer is and help us determine how a man’s recurrence may be ultimately treated—whether that is with local or systemic treatment. Again, this is a really anxiety-laden situation. We’re fortunate to have these new exciting imaging technologies for patients and their clinicians, which Prostatepedia discusses at length in this edition.

We use these imaging technologies in men with biochemical or PSA-only recurrence to help us understand where the cancer is located. For some men, these new imaging techniques might show us that there is a cancer recurrence in the pelvis where radiation can be given to potentially cure them of recurrent prostate cancer. That is a huge win, progress for our patients, and of course, wonderful news for the men and their families.

For other men, it is possible that we will not necessarily find recurrence, even with new imaging techniques. In those cases, we often continue to wait and watch. Biochemical recurrence can be challenging psychologically because knowing that your PSA is rising can be stressful, and the data explaining the best approach to treatment is not complete.

For men who have a single area of prostate cancer that has come back, whether as a single bone lesion or a few locations, advances in therapy for oligometastatic disease have come fast and furious. In this issue, Dr. Piet Ost talks about oligometastatic prostate cancer and how we might use radiation or surgery to treat a small amount of recurrent prostate cancer. Several clinical trials are working hard to figure out if treating this low volume of prostate cancer in single areas will potentially cure men of recurrent cancer.

It’s really important that we have new treatments we can use for men with hormone-sensitive metastatic prostate cancer, too. Over the last few years, we’ve seen men with metastatic hormone-sensitive prostate cancer live well for many years with several options for treatment. New data describing chemo-hormonal therapy or androgen deprivation therapy (ADT) with Zytiga (abiraterone acetate) have been incorporated quickly into clinical practice and are being widely used to help men with metastatic hormone-sensitive prostate cancer live longer.

Unfortunately, sometimes a man’s prostate cancer comes back more broadly, as a rising PSA only, or with sites of metastatic disease. This can be challenging physically, because sometimes it’s coupled with fatigue or pain as well as emotional difficulty. The cancer that a man thought was gone has now come back. To address this, there are many scientists and physicians working to try to help men with prostate cancer live better by using therapeutic advances as well as psychosocial and pain support teams that can improve patient-reported as well as disease outcomes. By incorporating social work and psychiatrists, centers are able to support men and their families, helping patients cope with PSA anxiety, which is an issue that can be anxiety-provoking and potentially go on for years at a time.

In terms of therapies, we as a field are very excited about new data that offers new therapies to men with biochemical recurrence who develop castration resistance before they have radiographic evidence of metastatic disease. Two clinical trials presented last month in San Francisco at the annual ASCO Genitourinary Oncology Symposium suggest that using either Xtandi (enzalutamide) or Erleada (apalutamide)—both androgen receptor-directed therapies—can prolong metastasis-free survival for men with castration-resistant non-metastatic disease.

This is a valuable advancement because any day spent without metastasis is a day spent feeling stronger and with less pain. We are also excited because both of these oral drugs have relatively low toxicities. Both clinicians and patients win when we add a significant amount of metastases-free time with a few pills and minimal side effects.

As a clinician, I understand the anxiety that drives the question: what if my cancer comes back? But this is a time of incredible hope. Medical advances are helping men live longer and live better, even if their cancers do come back.

Join us to read this month’s conversations about prostate cancer recurrence.


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Small cell? Or neuroendocrine cancer?

AparicioDr. Ana Aparicio is an Associate Professor in the Department of Genitourinary Medical Oncology at the University of Texas MD Anderson Cancer Center in Houston, Texas.

Prostatepedia spoke with her about rare but highly aggressive forms of prostate cancer.

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How did you become involved in such a specialized subset of prostate cancer research?

Dr. Aparicio: I was very frustrated by the fact that we treat homogeneously a disease that we perceive in the clinic to be heterogeneous. It drives me crazy that different people walk into the clinic with different diseases and yet we do the same thing to each and every one of them. This ends up meaning that many large Phase III trials are an enormous resource expense. It’s difficult to advance the field. I had remarkable responses for patients with Yervoy (ipilimumab) and yet the Phase III trial was negative. I felt like that was wrong. We should be smarter about what we’re doing. We need to understand the heterogeneity of prostate cancer and incorporate that understanding into clinical trials. Otherwise, it’s going to take us 200 years to make a difference in this disease.

I think of it in the following way. I take all of the prostate cancers and peel away the most aggressive ones. I then look to see how that relates to the rest of the disease. If we peel back in that way, we will start to understand the disease.

So then the work you’re doing can potentially change not only how we treat patients, but also how we design clinical trials?

Dr. Aparicio: Yes.

What is neuroendocrine prostate cancer?

Dr. Aparicio: Neuroendocrine prostate cancer is a histological definition of a prostate cancer variant. The prostate is composed of glandular tissue. When a pathologist looks at your garden-variety prostate cancer under the microscope, she sees it is composed of groups of glands. That is why it’s called adenocarcinoma: adeno meaning of or relating to the glands, carcinoma referring to the cancer arising from epithelial tissue. It’s cancer and not normal prostate tissue, but you can still recognize the glandular structures. Prostate adenocarcinomas respond very well to hormonal therapies.

On the other hand, small-cell prostate cancers basically look like sheets of cancer cells under the microscope. There is no glandular formation of any sort. These are small, round cells that have small amounts of cytoplasm (the gel-like material surrounding the nucleus) so their nuclei look very prominent. Small-cell cancers often express neuroendocrine markers, which are a type of protein expressed by a number of different tissue types and in a number of different cancers. Neuroendocrine markers are in no way specific to small-cell prostate cancers, but because the small-cell prostate cancers express them frequently, the other name that is given for small-cell prostate cancers is ‘poorly differentiated neuroendocrine prostate carcinoma.’ Many garden-variety prostate adenocarcinomas (those composed of groups of glands) also express these neuroendocrine markers. Again, the word neuroendocrine is not specific to small-cell cancers. Small cell refers to sheets of cells that are small with little amounts of cytoplasm.

The presence of small-cell cancer morphology on a surgical specimen or a biopsy is often associated with atypical clinical features for prostate cancer and a poor response to hormone therapies.

Garden-variety prostate adenocarcinomas most often spread to the bone and make round sclerotic (hardening) or osteoblastic bone metastases that show on a CT scan like a white patch.

In contrast, small-cell prostate carcinomas are often associated with what we call lytic (relating to disintegration) bone metastases, which show on a CT scan like a dark, punched-out hole. And that’s when the carcinomas go to the bone because they often don’t even show up in the bone. Men with small-cell cancer morphology can have exclusive visceral metastases, meaning their cancer has only gone to the liver, lymph nodes, or lung. They might also have bulky tumor masses, including bulky and symptomatic primary prostate tumors or bulky liver or lymph node masses. While they don’t respond well to hormonal therapies, small-cell prostate cancers often respond to chemotherapy.

A problem we ran into was that we would often find these atypical clinical features that I just described, but under the microscope where we expected to find small-cell prostate carcinoma morphology to justify chemotherapy, we didn’t. What happens when we see those atypical clinical features, but the biopsy doesn’t show small-cell morphology? Our experience shows that those people don’t do well with hormone therapies. In other words, when we do a biopsy and we find small-cell carcinoma morphology, we know that those cancers need to have chemotherapy sooner rather than later, as opposed to treatment with hormonal therapy. They need early chemotherapy as well; so we coined the term aggressive variant prostate cancers, which are tumors that share clinical features with small-cell cancers but may have different morphologies under the microscope. When we do a biopsy, they might look like adenocarcinoma, but they behave like small-cell cancer.

Join us to read the rest of the conversation.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


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Diagnosing Neuroendocrine Prostate Cancer

Prostatepedia spoke with Dr. Himisha Beltran, an Assistant Professor of Medicine at Weill Cornell Medical College in New York City, about diagnosing neuroendocrine prostate cancer.

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How is small-cell or neuroendocrine prostate cancer diagnosed? Biopsy? Imaging?

Dr. Himisha Beltran: Small-cell or neuroendocrine prostate cancer is diagnosed by tumor biopsy. The pathologist typically makes the diagnosis by looking at the morphologic features of the cancer under a microscope and may perform additional testing to look at expression of neuroendocrine markers or classical prostate markers to support the diagnosis.

One of the reasons why neuroendocrine prostate cancer was thought to be so rare was that doing metastatic biopsies on patients already diagnosed with prostate cancer was just not done in the clinic. It is only recently that we are recommending biopsies to look for neuroendocrine prostate cancer in select patients with aggressive clinical features and low PSA levels. Biopsies are also being considered to look for other emerging molecular targets. There are now several prostate cancer clinical trials targeting different mutations and alterations.

An obvious next step is to try to diagnose neuroendocrine prostate cancer noninvasively. Imaging is a noninvasive way to detect different cancers, but there hasn’t been any sort of imaging tool yet that can really identify these patients. We’re starting to see clues that there may be some molecular markers that are expressed that might help future research in this area. Another noninvasive approach we have been investigating is the use of liquid biopsies that include circulating tumor cells as well as circulating tumor DNA to see if there are clues that can help us identify these patients without a biopsy. This is still in research development.

 

 

 

 

 

Read the rest of Dr. Beltran’s comments on neuroendocrine prostate cancer.


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Neuroendocrine Prostate Cancer

Agarwal

This month, Prostatepedia is talking about neuroendocrine prostate cancer, an aggressive form of the disease.

Dr. Neeraj Agarwal,e Director of the Genitourinary Oncology Program in the Oncology Division, the Co-Leader of the Urologic Oncology Multidisciplinary Program, and the Associate Director of Clinical Trials at the Huntsman Cancer Institute at the University of Utah, offers his insights into this month’s discussions.

Not a member: Join us to read the conversations about neuroendocrine prostate cancer.

 

Until 2010, the only drug treatment we had for advanced prostate cancer was chemotherapy with Taxotere (docetaxel). Since then, we have seen the advent of many new drugs, including the drugs to target androgen signaling. Androgen signaling is a critical player in prostate cancer progression. Testosterone is needed for prostate cancer as a fuel; testosterone interacts with the androgen receptor, which is necessary for transcription within the prostate cancer cells.

These drugs induce a deeper blockage of androgen signaling. They include Zytiga (abiraterone) with prednisone, which diminishes the production of testosterone within the prostate cancer cells and adrenal glands, and Xtandi (enzalutamide), which is a next-generation androgen receptor blocker. We also have several new drugs that target androgen signaling in similar fashions such as apalutamide (ARN-509), and darolutamide (ODM-201).

However, over the past five years, we have observed that literally every patient experiences disease progression on these newer androgen signaling targeting drugs. When they progress, some unique features are seen. In approximately 25% of these patients, their PSA values do not necessarily go up in proportion to their disease burden, while their scans show disease progression. This phenomenon is what we now call androgen indifferent prostate cancer, or neuroendocrine prostate cancer.

Neuroendocrine or androgen indifferent prostate cancer existed in the past. A small number of patients—maybe 5%—have neuroendocrine disease from the day they come in for their first biopsy. But now, as these patients are living longer, courtesy of the new androgen signaling inhibitors, the prevalence of neuroendocrine prostate cancer has been increasing steadily. These patients do not really respond well to further manipulation of androgen signaling.

We don’t have standard guidelines in place to diagnose neuroendocrine or androgen-indifferent prostate cancer, so physicians are not always sure what to do when they see this unusual presentation of prostate cancer. Many renowned experts, such as Dr. Ana Aparicio or Dr. Himisha Beltran who are featured this month in Prostatepedia, are working on diagnosis, treatment, and establishing biomarkers for these patients.

From a clinician’s perspective, I can tell a patient has neuroendocrine or androgen-indifferent prostate cancer when I notice disease progression on the scans with disproportionally low PSA levels, and an increase in other tumor markers, such as LDH (lactate dehydrogenase) and alkaline phosphatase.

If you notice these features I recommend consulting with an expert who specializes in neuroendocrine type prostate cancer. Seek out an NCI-designated comprehensive cancer center where oncologists are specializing in prostate cancer, and are likely going to be more familiar with this form of prostate cancer.

I think it’s worth spending extra time, money, and effort up front for the correct diagnosis and a more appropriate treatment plan.

Subscribe to read Dr. Aparicio and Dr. Beltran’s comments on neuroendocrine prostate cancer.


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Xtandi V. Zytiga: Cognitive Effects?

Alicia Morgans, M.D., Hematology/Oncology

 photos by Susan Urmy

 

Dr. Alicia Morgans, a medical oncologist, specializes in treating advanced prostate cancer and is particularly interested in addressing treatment side effects.

In July, Prostatepedia spoke with her about her clinical trial that looks at the cognitive effects that Xtandi (enzalutamide) and Zytiga (abiraterone) can have.

 

 

Dr. Alicia Morgans: My research focuses on understanding the complications of cancer survivors and, specifically, understanding the complications of hormonal manipulation in men with prostate cancer. I’ve done work investigating osteoporosis and bone complications, cardiovascular complications, and metabolic complications like diabetes. The one area that I had not really explored, and that has been underexplored in the field, is the possibility that there may be cognitive changes associated with the hormonal therapies we use.

A patient who served as an inspiration for the study was a preacher who I met a few years ago, just a few weeks after his urologist started him on Xtandi (enzalutamide). His family was concerned because he developed a profound change in his motivation and planning skills, and he was unable to give sermons since starting the medication.

We were able to stop the medication, and a few weeks later, everyone said that he was back to normal. I just needed to understand why this might be the case. This led to the development of our study.

We are comparing the cognitive function of men starting Zytiga (abiraterone) or Xtandi (enzalutamide) over time to see if there is any difference between drugs that block the androgen receptor like Xtandi (enzalutamide) and drugs that just lower testosterone levels more completely like Zytiga (abiraterone).

Both of these drugs are used in the same patient population and are tremendously effective at controlling the cancer, so this comparison could be done safely.

I was fortunate to have some incredible collaborators with experience in traditional neurocognitive testing help develop the study protocol. In addition to comparing cognitive function between groups, the study validates a computer-based cognitive testing system (Cogstate) against traditional neurocognitive pen-and paper tests in the prostate cancer population. If the measures appear to provide similar assessments, I hope to integrate computer-based cognitive testing into many prospective therapeutic studies just as patient reported outcome measures of pain, fatigue, and depression have been.

Finally, I have to mention that we were very fortunate to pique the interest of the Prostate Cancer Foundation in this work, and they were incredibly generous in conferring an award to fund the study.

Their award allowed us to integrate an assessment of possible genetic predisposition to developing cognitive dysfunction. The award also provides funds to integrate advanced neuroimaging with a noninvasive MRI series into the protocol. This will enable us to look at structural and functional changes that may happen in the brain during treatment.

We are doing this trial now because it is definitely an area of clinical concern in my practice. I don’t think that previous work has been able to nail down which populations are at highest risk for cognitive dysfunction or develop a methodology that is both reliable and reproducible in larger scale settings. Our trial design may validate a computer-based methodology that can be expanded to other sites without requiring that trials include psychologists with neurocognitive expertise to administer cognitive tests. The computer-based method is less resource-intensive and more easily scalable.

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