Tag Archives: prostate cancer

Of Prostates and Teslas


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If you thought this might be an article about how your urologist shops for his/her newest fancy car, you are mistaken (sadly…). Nikola Tesla was a fascinating inventor and ultimately “mad scientist” at the turn of the last century. Every time you plug your cuisinart into the wall to chop something up, you are the beneficiary of his contributions to the alternating current coming to your kitchen and the motor driving the chopper. My favorite story (because of the local connection) was his laboratory in Colorado Springs, where he attempted to develop a method of transmitting power without wires. By creating YUUUGE electromagnetic fields, he could make lots of electrical things happen at considerable distances, including knocking out the power station for the city. Here’s a quote from the Wikipedia article:

He produced artificial lightning, with discharges consisting of millions of volts and up to 135 feet (41 m) long.[11] Thunder from the released energy was heard 15 miles (24 km) away in Cripple Creek, Colorado. People walking along the street observed sparks jumping between their feet and the ground. Sparks sprang from water line taps when touched. Light bulbs within 100 feet (30 m) of the lab glowed even when turned off. Horses in a livery stable bolted from their stalls after receiving shocks through their metal shoes. Butterflies were electrified, swirling in circles with blue halos of St. Elmo’s fire around their wings.[12]

Of course, for purposes of this blog, the key thing is that the strength of magnetic fields was named after him. When you get an MRI of your prostate, brain, or anything else, you are put into a machine with a superconducting magnet that produces 1.5 or 3 “T” of strength. At the risk of being completely wrong and oversimplifying, what happens in the MRI machine is that a strong magnetic field temporarily lines up the hydrogen atoms in the water that is 70% of “you”, and when these atoms “relax” they give off radio signals that can be converted to images. Details and images are here. Early on, my colleagues and I were fascinated by the possibility of using MR to investigate the prostate gland and published an article (completely ignored – cited only 3 times, so must not have been that important…) showing changes in MR that occurred after testosterone administration to castrated rats.

Now there are complex MRI protocols to image the prostate using techniques I don’t fully understand (multiparametric imaging) that give us remarkable pictures of the prostate gland. Here is one:

Screen Shot 2018-01-10 at 1.53.20 PM

Prostate gland with red arrow indicating a suspicious lesion that could be biopsied or followed closely.

As with any radiologic imaging technique, the skill of the radiologist as well as the equipment being used determine the accuracy of the MRI to diagnose a cancer.

While most of us learned how to “read X-rays” in medical school, it is beyond most clinicians to read MRI’s of the prostate. Fortunately, the radiologists have developed a system that helps us think about “how abnormal” some area of the gland is, called PI-RADS.  This can be very useful in thinking about what area to concentrate on when biopsying a patient, or in trying to determine whether surgery or radiation therapy should be altered if there is concern that the cancer is outside of the gland. An interesting question that is still controversial is whether the MRI could replace repetitive biopsies in a man who has chosen active surveillance. Particularly when combined with molecular techniques (see my previous blog here) to characterize biopsies, it may be that Tesla will be helping to do more than get you from one place to another or run your electric shaver. (Rock on, Elon Musk) To me, that is a pretty interesting outcome from knocking out all of the lights in Colorado Springs!

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23 & You – Genetic tests for pca


The genetics of prostate cancer are daunting, but there are now a range of tests available that could be used at almost every stage of the disease IF you can deal with the answers you are likely to receive. Generally these tests are the product of science that goes something like this: A complete molecular picture is taken of all the mutations or all the genes expressed in a series of prostate cancer patients diagnosed years ago. For these patients “all you need to do” is go back to the paraffin blocks that were saved for each patient, extract the DNA/RNA and quantify gene expression and any mutations that can be detected. A decade ago, the technology for doing this was daunting, but now it is relatively easy. Once you have the gene expression profile, you can ask a computer to look for gene expressions that correlate with a certain outcome. For example, you take 500 patients from one center for whom the outcome is known…50 patients are dead, 32 from prostate cancer…70 patients developed metastases by 5 years…these 315 patients are alive and well with no evidence of recurrence…etc. Let’s say there are 50 genes that show changes in expression or mutation. Do we need all 50 to forecast what happened to the patients in that group? No. A computer algorithm can keep testing combinations and permutations of genes and reduce the 50 to a smaller number. We can either let the computer pick the final genes, or we could start with genes we think are related to tumor progression and then do the reduction. In the end, we have a small number of genes with characteristics that accurately separate the patients into “good” and “bad” groups and everything in between. We now take our gene panel, reduced to something like a computer chip and apply the test to 500 patients at another institution blinded from what actually happened to those patients. If our algorithm works, we should be able to accurately predict what happened to those patients in the next 5 or 10 years. If it works, our testing system has been validated, and we can begin offering the test to newly diagnosed patients at some stage of illness. For example, a Gleason 3+4=7 patient might fall into a group where surgery produced a 90% chance of being cured at 10 years, or a 40% chance depending on the gene expression. BUT…and this is key…what to do about the result is still a complex decision for both patient and physician. If you are a Gleason 3+3=6 patient and with no treatment at all you have an 85% chance of “cure” at ten years, is that good enough? What if it is a 95% chance? Will that make you more comfortable choosing no treatment, or do you want to be cured at any cost (impotence, incontinence, other side effects of radiation or surgery)?

As none of these tests has been proven in a prospective study – that is, using the tests to do something like even more aggressive therapy in a group of high risk patients, we are still in the early stages of understanding how and when to use them. Fortunately, my colleague, Dave Crawford and some colleagues have put together an excellent website to help patients/doctors understand the tests. http://www.pcmarkers.com has a list of most of the available tests and you can see what results might look like before you and your physician decide to send one off. This is a rapidly evolving field however, and not every test that is being commercialized is listed, and at big centers, there are always new tests being developed.

Finally, as with all of medicine, the payment systems/insurance coverage is crazily complex. Only today, I received an email with the “news” that a cardiologist/congressman, Rep. Buchson has introduced a bill called the “Prostate Cancer Misdiagnosis Elimination Act of 2017” that uses DNA profiling to make sure the tissue being tested is yours. You could theoretically apply this test to ANY cancer biopsy of course, so why prostate cancer? Then there is the motivation…call me cynical, but I suspected that the good congressman, meddling in medicine, might have a local connection, and sure enough, the company that markets the test is from his home state, Indiana. Not to say it isn’t important to know that tissue being tested comes from the correct patient or that the test isn’t a nice application of the kind of technology that identified OJ’s blood, just that we live in interesting times where medical technology is rapidly consuming more and more of our tax/insurance/personal dollars. Personalized medicine will depend totally on this type of technology and can be incredibly expensive. Whether it saves money or consumes it may depend on how many “worthless” (for that patient…and is a treatment with only a 5% chance of working really worthless??…not if you are in the 5% group) treatments are avoided and at what cost. I don’t have the answers. Hopefully this blog at least helps you begin to understand the current molecular diagnostic landscape.

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A statin a day??


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I remember when the statins first came out in the late 1980’s. I had a mildly elevated cholesterol that didn’t respond much to the dietary changes (admittedly few) I was willing to make, so taking a statin seemed like a great step forward. But… were they safe? Of course the same could be asked of aspirin, bike riding, eating meat, or skiing. It’s really about risk/benefit in the end. In the years that followed, I ended up taking statins with the permission of my doctor and they work far better than dietary manipulation for my cholesterol and I combine their use with exercise for all of the other benefits (read here). I previously posted about statin use here, but there are new data all the time worth keeping up with.

In a recent JCO article, a large group (31,790) of Danish men were evaluated for prostate cancer specific and overall mortality depending on their use of statins. Even though there was a higher mortality from prostate cancer than is usually seen in such studies (23% – potentially because there is lower use of screening in Denmark), the prostate cancer specific death rate and overall death rate was 15-20% lower in the men who took statins after diagnosis. This was regardless of their treatment (surgery, radiation, hormones). Since I mentioned aspirin, other studies have suggested that men with high Gleason scores (≥8) may benefit from aspirin use as well. Statins have also been shown to inhibit a long list of other cancer causes of death that you can read about in Wikipedia, so the benefits to prostate cancer patients, who often die of other cancers or cardiovascular disease is not limited to their concerns about prostate cancer itself.

In an editorial accompanying the JCO article by Mucci and Kantoff, there is a thoughtful review of whether statins should be recommended for all men with prostate cancer. The article also discusses how they might work to slow down prostate cancer, so be sure to read it for the excellent summary. They conclude that the evidence is still not there, although certainly the large number of studies and meta-analyses they provide make a strong case. My question would be “what is the risk?”, and it seems to be minimal. Statins are cheap and widely available. They provide risk-lowering effects on cholesterol/heart disease, and the only side effect that is a problem in general is the muscle pain that occurs in some patients, which almost always goes away when you stop the drug. I can’t disagree with the thought that a prospective randomized trial in a subgroup of prostate cancer patients is desirable, but in the absence of such a trial to invite patients’ participation, I personally encourage patients to take statins unless their primary care physician disagrees. For that matter, I would almost encourage their presence in the water supply like fluorides given all their other benefits (just kidding, but they really do have a long list of benefits and very favorable risk profile in my view).

An apple a day is a good idea. Statins should maybe join that, and keep exercising!

 

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3 Articles and a forth


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OK, I admit to a sleazy, seemingly misspelled word to attract attention. At least I didn’t tweet it at 3AM. So what about the “forth”? I’m using it to remind you to sally forth in your search for information about prostate cancer. I previously wrote a blog giving some practical instructions on how to find the latest research publications on prostate cancer that you can find here. Another possibility, if you want to be overwhelmed is to subscribe to the Prostate Cancer Daily, published by Uro Today. So far as I can tell it is open to all, presents the original abstracts, and links via PubMed to the article itself. I now realize that the prediction of patients knowing more than their doctors about a given condition is glaringly obvious, something I discussed when I first wrote about the Internet and Oncology two decades ago.

So, on to the 3 articles: Typically, the most important articles in medicine are published in high profile journals. The premier one for medical oncology is the Journal of Clinical Oncology, JCO. The editors recently published a “best of genitourinary cancer, 2017” edition in coordination with what we medical oncologists call “GU ASCO” (actually co-sponsored by ASCO, ASTRO, and SUO). I thought it would be of interest to briefly re-cap the 3 prostate articles chosen for that edition.

ARTICLE 1: Enzalutamide Versus Bicalutamide in Castration-Resistant Prostate Cancer: The STRIVE Trial. This study compared the more potent anti-androgen, enzalutamide (Xtandi™) to the older drug, bicalutamide (Casodex™) in patients who had become resistant to initial hormonal therapy. About 2/3 of the men had positive scans, while in 1/3 the resistance was detected only by a rising PSA without a positive scan. As we might have expected from the way enzalutamide was developed, it was clearly superior, with progression free survival of 19 months for enzalutamide vs. 6 months for bicalutamide. In an ideal world, we would use enzalutamide instead of bicalutamide in almost all cases where an antiandrogen is indicated. However, the increased cost of this drug is dramatic, and there may be other options or confounding issues with interpretation of the study.

ARTICLE 2: Randomized Phase III Noninferiority Study Comparing Two Radiotherapy Fractionation Schedules in Patients With Low-Risk Prostate Cancer. This article reports on one of many studies looking at whether radiation therapy treatment times can be safely shortened by increasing the dose of radiation given with each treatment and giving fewer treatments (fractions). The underlying principles are that tumor cells cannot repair DNA damage from radiation as quickly as normal cells, so giving radiation in small fractions daily allows killing of the tumor while normal cells repair most of the damage. Giving all of the radiation at once would kill every cell (and the patient).  Experimentally, prostate cancer cells may be more susceptible to larger fractions, and this study demonstrated that a radiation therapy course could be safely shortened from 41 sessions to 28 sessions with similar “cure” rates at 5.8 years of followup. This is a general trend in radiation therapy for prostate cancer. Using newer radiation focusing technologies (IMRT, IGRT, Stereotactic radiosurgery, etc.) it is possible to treat prostate cancer with as few as 5 treatments, although the long term efficacy is still unknown, and the addition of androgen deprivation to radiation treatment at any dose also improves efficacy. How to combine these approaches, the optimal duration of ADT, and which patients should stay with the older methods is still uncertain.

ARTICLE 3: Improved Survival With Prostate Radiation in Addition to Androgen Deprivation Therapy for Men With Newly Diagnosed Metastatic Prostate Cancer. Proudly, many of the authors on this article are from the University of Colorado Cancer Center. The authors used the National Cancer Database to determine whether patients with metastatic prostate cancer, traditionally treated with hormone therapy (ADT) only (although more recently with hormone therapy plus chemotherapy) benefit from also radiatiScreen Shot 2015-10-30 at 11.02.16 AMng the prostate itself. The analogy would be burning down the barn after the horse has left (with apologies to my radiation therapy colleagues who never like to compare radiation
treatments to burning). The patients who had their prostates radiated
had a 5 year survival of 49% compared to 33% for those receiving ADT alone. Removing the prostate surgically also worked. The prostate may also be a site where metastatic cells from another location return, as illustrated in this picture and discussed here. The take home message is that the cancerous prostate may continue to “seed” cancer cells to the rest of the body, or be a home for circulating tumor cells and getting rid of it, even though not curative, may be a good idea (toxicities and costs aside).

Consider yourselves updated! (sort of…)

 

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No pain, no gain?


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One of my patients last week had a heartfelt discussion regarding the survival benefit of ADT vs his quality of life. He enjoys body building and showed me some pretty dramatic pictures of himself during his last ADT cycle (on intermittent therapy) versus now, when he had been off treatment for ~6-9 months. Added to his concern was his decline in libido and sexual function during ADT, a common complaint especially among younger patients. The question of quality vs quantity of life was,of course, utmost on his mind.

Starting from the initial diagnosis, every (maybe that should be every !!) prostate cancer patient will experience a decrement in quality of life. Those who elect “watchful waiting” will nevertheless experience anxiety regarding the shadow of CANCER following their footsteps. Sure, you can put it out of your mind, but turn around and there it is, like the neighbor’s unwanted cat stalking you. Then there is the anxiety over what the next PSA will be. And if on active surveillance, what will that next biopsy show?? These issues are both real, disturbing, and often under-appreciated in the discussions surrounding screening…”we should still be screening, but not treat the men who don’t need it…” Really? What about the 80% of men who die at age 90 with prostate cancer at autopsy who never had to deal with the shadow? (The inevitable counter-argument is, “yes, and what about those who had early detection of a high grade cancer whose life was saved?”)

We also tend to ignore the impact of competing mortality in our discussions. “Sure you had a stent placed last year, and you already survived that small colon cancer, so why wouldn’t we be aggressive in treating this new problem?” Dr. Sartor provided an elegant discussion of this in an editorial on the PIVOT trial you can read here. Whatever the flaws in that study, it remains clear that we are not very good at predicting the non-prostate cancer “future” for our patients, and the older you are, the thinner the ice gets regardless of how many marathons you run.

When patients choose one form of primary treatment vs another, they are weighing the different side effect profiles of surgery or radiation as much as which is “most effective”. I often give patients a copy of this article from NEJM and encourage them to spend some time looking at the graphics in Figure 1 to get some idea of what they will face in the way of side effects from treatment. As any honest physician would tell them, treatment will involve side effects, some permanent, in the best of circumstances.

In the setting of more advanced disease, for example a patient who presents with metastases outside the pelvis, the recent CHAARTED and STAMPEDE trials both suggest an advantage to the earlier use of docetaxel chemotherapy in combination with ADT as opposed to ADT alone. These data suggest that “pay me now or pay me later” analysis favors the “pay me now” approach in terms of overall survival. But at what price for quality of life? Fortunately most chemotherapy side effects are reversible, but distinctly unpleasant, potentially making the equation something like “4 months of misery to provide 14 months of longer life….not all of which will be great anyway”.

Even in the very advanced setting, there is some evidence that greater toxicity results in improved survival. A recent analysis of the TROPIC trial of cabazitaxel suggested that the patients who had the most “toxic response” in terms of dropping their neutrophil count benefited the most in terms of overall survival.

While all of this seems incredibly negative (for which I apologize), the history of oncology as a field has been the incremental improvement in survival AND the development of newer treatments that provide such advances with diminishing toxicity. Pediatric leukemia, as discussed extensively in “The Emperor of All Maladies” is a great example of how pioneering patients and physicians worked together to find cures and reduce side effects. We may only be at the beginning of such achievement in prostate cancer, but with the advent of the newer hormonal and imaging agents, increasingly sophisticated surgery and radiation, vaccines and immunotherapy, and even the chemotherapies now available, we have  no doubt reached the end of the beginning. Onward!

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Olaparib for resistant prostate cancer


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In what is the first (and hopefully one of many) example of using modern genomic methods to match treatments to the molecular defects in prostate cancer, the FDA has just granted “breakthrough designation” to olaparib, a drug made by AstraZeneca. This followed a publication in the NEJM with nearly as many authors as patients, illustrating the power of team science and international collaboration.

Cancer cells develop numerous mutations that provide them with the ability to divide, metastasize, escape immune surveillance and so forth. One of the drivers of this mutation cascade is genetic instability, in part due to the accumulation of mutations that keep the cells from correcting DNA alterations. These mutations in DNA-repair enzymes can leave the cancer susceptible to additional inhibitors of DNA repair, one of which is PARP, an enzyme found in the nucleus that detects DNA strand breaks and initiates repair. When olaparib interferes with this enzyme, cells can become so genetically unstable they die.

In the TOPARP-A trial, 50 patients who had castrate resistant prostate cancer and had progressed on second generation anti-androgen treatment and docetaxel were given olaparib. 16 of 49 evaluable patients responded, however the exciting finding was that because these patients participated in the clinical trial and allowed the investigators to biopsy their tumors, it was possible to relate response to the presence of defects in the DNA repair genes. For this subgroup, 14 of 16 responded, indicating that using the repair defects as a biomarker you could predict high response rates, while at the same time, patients without such genetic defects had a much lower response rate (2/33). There is an excellent video that illustrates the results accompanying the publication that you can find by clicking here.

Although this is terrific news for prostate cancer patients, it brings a number of challenges. Testing for genetic mutations is a growing (and somewhat expensive) process. When compared to giving patients a drug that predictably won’t work, however, it can be very cost effective. Second, when you biopsy a tumor, the results can vary depending on where you biopsy as I discussed in this previous blog. “Liquid biopsies” of circulating DNA or tumor cells may provide some help in meeting this challenge.  Third, responses to targeted therapies such as olaparib tend to be rather short-lived, as the cancer cells continue to mutate to find ways around the new agent. The hope would be that combining a targeted treatment like olaparib with an immune approach might bring more prolonged responses. Finally, we must find a way to deal with the extraordinary costs of the new oncology drugs. The actual cost of olaparib is $13,440/month according to this article in the ASCO post. I have previously opined on this issue and invite you to join the discussion by clicking here.

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Prostate Drug Costs


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Most readers will have seen something in the popular press over the last 6 months regarding the increasing awareness of oncology drug costs. For example, there have been very nice commentaries in the New England Journal of Medicine like this one, that deals with the cost of nivolumab, a PD-1 pathway inhibitor that is approved for treating melanoma and may show promise in a number of other cancers like kidney cancer. The final paragraph is telling:

Hand clapping for science is now inextricably linked to hand wringing over affordability. Drug prices are increasing more rapidly than their benefits, and the growth in spending on drugs has started to outstrip growth in other areas of health care. Addressing this problem requires realizing that cost-effectiveness assessment — a step that we are not even ready for in the United States — has limitations when one considers the price of the comparator and the impact on overall budgets.

I have opined elsewhere in this blog site on the excitement over the new immune-stimulating drugs that show promise. Indeed, some may be able to improve the response to prostate vaccine approaches. The question is whether we can afford all of these drugs, who decides, how they decide, and what methods they use. In the past, a QALY (quality adjusted life year) has been used to benchmark some of the things we do in medicine. In a nice NEJM perspective article, the classic “$50,000/QALY” benchmark was reviewed, but the authors suggested that given medical progress and inflation, a more realistic number might be as high as $100,000 or $150,000. The costs of the newer prostate cancer drugs such as abiraterone, enzalutamide, sipuleucel-T, cabazitaxel etc. have not escaped attention. Medscape had an article on this over 2 years ago. I am no expert on Markov models, differing ways to evaluate cost-effectiveness, and the economics of medicine. But as a simple way of explaining the challenge, how much is cisplatin, a cornerstone of curative treatment for testis cancer, the number one cancer of young men in their 20’s worth? If you can answer that, then how much would it be worth if you were using the same drug as a third line to treat prostate cancer, where responses are rare except in the case of the small cell variant, but no one is cured? In the case of the young testis cancer patient, many years (or QALY’s) are achieved while in the case of even the “sensitive” form of prostate cancer, the benefit would be in months at best. Should testis cancer patients have to pay huge sums because it works so well for them and prostate cancer patients less? And how do we figure in the drug development costs in a fair way that retains a financial incentive for the pharmaceutical companies and researchers to keep working for new discoveries?

Added to this is my own experience when I have described using a highly expensive (sometimes toxic) drug to a patient with well-known, very limited (but measurable, approved, and “covered” by Medicare or insurance) benefit. Often when I am honest and say, “this may help for a while, but is not a cure,” to a patient who may have very few symptoms at all but is progressing based on a rising PSA, the reply will be “what choice do I have”? That is a great question. If someone else is paying for some very expensive drug, why not try it? Although I know that the ethicists feel “my wishful answer” is unethical, I would like to be able to say something like this: “Well Mr. Smitherton, Medicare has decided that if you would rather take the money and apply it to your grandchild’s college fund, they will be willing to divert the costs (or some proportion of them) to that cause because ‘we’ [society] feel that should be your choice, rather than having us pay for a relatively ineffective, expensive drug if you don’t think it is worth it, or if you value his/her education over a few months of additional life span.” If wishes were horses, beggars would ride. And if I was qualified in ethics, I would probably not be writing this. That’s my 2¢ – or maybe it should be my $20,000??

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