As part of our coverage of the 2015 ASCO Genitourinary Cancers Symposium, we are speaking with John L. Gore, MD, associate professor in the department of urology at the University of Washington School of Medicine. Dr. Gore is speaking about individualized treatment decisions for men with localized prostate cancer at the meeting.
— Interviewed by Anna Azvolinsky
Cancer Network: Dr. Gore, let’s start with the management options available for patients with localized prostate cancer.
Dr. Gore: Prostate cancer is a difficult condition for a number of reasons. But in localized prostate cancer, it can be particularly tricky to navigate because the treatment options are equally effective in managing the cancer but offer a range of potential treatment side effects. In general, the treatment options range from interventions with surgery, radiation, or ablation, or more observation-based algorithms. Surgery involves removing the prostate either through an open incision or small keyhole incisions, and with the use of robotic technology, the prostate is removed, and the bladder is sewn directly to the urethra.
With radiation, there are a number of ways to deliver radiation to the prostate. The most common way is external beam radiation; some of the major technological advances of the last 10 to 15 years are ways to deliver high doses of radiation to the prostate but in a very focused way, so that there is less of an innocent-bystander effect of external beam radiation than there was 10 to 15 years ago. The common ways that radiation might be delivered is through 3D conformal radiation therapy or intensity-modulated radiation therapy. One emerging strategy we are seeing used more and more these days is stereotactic body radiation therapy, which is also sometimes called robotic radiotherapy. There is also proton beam radiation therapy, which garners a lot of press. There is also interstitial radiation therapy, in which patients have radioactive seeds placed into the prostate that kill cancer cells.
Then there is ablation, in which either heating or cooling technology is applied to the prostate to kill cancer cells. The most common technique is called cryoablation, in which the prostate is frozen, essentially. There is another technique that is not approved in the United States, which is high-intensity focused ultrasound to the prostate.
It should be noted that not every prostate cancer needs to be treated. Prostate cancer is a particularly slow-growing cancer and we know from long-term large-scale cohorts that among the men who have prostate cancer, it is only a small fraction of patients that actually die of their prostate cancer. One emerging management strategy that has really become prominent in the last 5 to 10 years is active surveillance. That language is very carefully selected. When you look at the larger active surveillance cohorts in the United States and abroad, they all employ some sort of strategy that involves repeat prostate-specific antigen (PSA) examinations and repeat biopsies to re-establish how severe the cancer is. It’s this idea that even though we are not going to actively, aggressively treat you, we are going to watch it closely.
Cancer Network: What are some of the decision aid resources available for clinicians and their patients in choosing the best localized therapy? It seems like there are a lot of options.
Dr. Gore: That list we just talked about is a big reason why it’s such a confusing situation—that’s a laundry list of potential options and when you are told that each option, in its own way, offers the same chance of success, for most patients, it can be very tricky to choose. Decision aids have been focusing on clinically localized prostate cancer—cancer that is confined to the prostate for a number of years. There have been a number of research studies that looked at decision aids and how they can inform patients and reduce what is called “decisional conflict,” people’s internal dilemma when confronted with a challenging decision like a [treatment plan] for a cancer diagnosis. The main goals for a lot of these decision aids are, number one, to inform, in this case, men about their available options, and two, to clarify their values and preferences—not only to tell them what is available but to help them understand what, relevant to their cancer diagnosis, is important to them. There are a number of ways to do that. In general, most decision aids have a component where they question patients about their preferences—in the case of prostate cancer treatment, the things we are most concerned about are things like urinary continence, other urinary symptoms, sexual function, and the idea of having the cancer reside in the body.
There are a number of resources that are publically available. The Agency for Healthcare Research and Quality, which is part of the National Institutes of Health, has an online decision aid that helps patients go through their preferences, which actually was built based on a report of their effective healthcare program, a rigorous evidence-based review. The Informed Medical Decisions Foundation has some accessible decision aids. A lot of the decision aids patients might find when they look on the Internet are about prostate cancer screening—should I have a PSA blood test to evaluate for my risk of prostate cancer? But there are also a number available for prostate cancer decision making. A lot of academic and non-academic centers have their own programs with decision support aids, so it’s a great opportunity for patients to ask their clinicians about what decision aids they have available.
Cancer Network: Can you highlight some of the quality-of-life outcome studies that aimed to facilitate these treatment decisions for localized prostate cancer?
Dr. Gore: One of the big transitions that happened in prostate cancer care in the 90s was the recognition that what a physician says about the patient’s outcome is not necessarily an accurate reflection of how that patient is doing. Mark Litwin, MD, at UCLA did this phenomenal study with a registry called CaPSURE that is run out of the University of California, San Francisco, where they looked at physicians’ perceptions of their patients’ quality-of-life outcomes and patients’ actual quality-of-life outcomes, and as you can imagine, they were very different. Physicians frequently overestimated their patients’ function after prostate cancer treatment, so this idea of patient-reported outcomes is really critical in prostate cancer quality-of-life measurement. And over the next 10 to 15 years there were a number of registries that captured quality-of-life outcomes for patients treated in the community, patients that were derived from cancer registries, and patients that were treated at academic centers.
Besides CaPSURE, some of the common cohorts are PCOS, the Prostate Cancer Outcomes Study, which uses National Cancer Institute registry patients and catalogs their outcomes. They recently published on 15-year outcomes, which are incredible, long-term outcomes. They have an update called the CEASAR study, which is looking at some of the newer treatments that patients are getting for their prostate cancer. There is also PROSQA, a multi-center collaboration between academic centers, which is unique because it not only captures outcomes from patients’ self-reports but also their partners’ outcomes and what the partners say about the patient outcomes.
Cancer Network: Just briefly, what are some of the important, outstanding questions on how to make the best management decisions for localized prostate cancer treatment?
Dr. Gore: In the emerging technologies and capabilities of tools that are now available that were never available for clinical care are iPads. We now have an opportunity to figure out how to get some of these quality-of-life outcomes more readily that are more usable in the clinic. The idea of clinically integrating quality-of-life measurements is going to be something we are going to see a lot more, where patients who present to their prostate cancer clinician are able to capture their quality-of-life outcomes, track them, and answer important questions about them, like, “How am I doing compared to how I was before treatment?” “How am I doing compared to other men who have had this type of treatment?” “What can I expect in the future?”
So, not only using tools that bring some of these registry results into clinical practice but also individualizing some of those outcomes. If you check out the resources I mentioned, you will be presented content about the outcomes of men who have surgery. The decision aid will say that urinary incontinence is higher with surgery than with radiation, which is true. What we call storage symptoms like urinary frequency and urgency are much more common with radiation than with surgery. So, generic platitudes are presented about these treatments, but where I think the future is headed is really more individualized approaches—what the right treatment is specifically for the individual based on his values and quality of life before treatment, as well as what one can expect for recovery based on other men or based on personalized outcomes, to see if he is on pace with survivorship care or lagging behind. If necessary, we need to be able to think about doing secondary treatments for things like impotence or incontinence.
Cancer Network: Thank you so much for joining us today, Dr. Gore.
Dr. Gore: Thank you very much.