Patient Scenario 3: A 75-Year-Old Man With Metastatic Hormone-Sensitive Prostate Cancer
In a third clinical scenario of metastatic hormone-sensitive prostate cancer, panelists discuss oligometastatic disease, radiation therapy, and the potential role for PSMA-PET scans.
Transcript:
Alan H. Bryce, MD: Let’s go to case 3. Now we’re talking about an older man. I get a lot of golf cart crashes in Scottsdale for some reason. Something to do with the Waste Management Open. This patient comes in with pain after a crash. He felt fine beforehand. He’s bruised up. They get a scan, and he’s got an enlarged prostate and a sclerotic bone lesion at L2. PSA [prostate-specific antigen] level at 32 ng/mL, which is nothing too dramatic, and a prostate biopsy shows Gleason 4+3 adenocarcinoma. You can see his genetic results here. There are no pathogenic variants in the germline. TMPRSS2-ERG, PTEN are very normal and standard prostate genetics. Dr Zhang, how about systemic therapy? One bone metastasis, with the primary [tumor] still in place. What’s the decision-making for this patient?
Tian Zhang, MD, MHS: In oligometastatic disease, we still start with systemic therapy. These patients are potentially good candidates for doublets. We’d be talking about Lupron [leuprorelin] to start and then abiraterone, apalutamide, and enzalutamide, and then we’ll see how they do over time. Based on STAMPEDE, 6 to 12 months would be a great response. I’d also be thinking about radiating the prostate. Based on STOMP and ORIOLE trials, I’d be thinking about radiation to the oligometastases as well. I think of these as relatively standard for what we see for genetic alterations. They’re pretty standard for what we see. PTEN deletions can be a little more aggressive, but they tend to respond to AR [androgen receptor]–targeted therapies. Unfortunately, we have a negative trial targeting AKT or PTEN for all comers, but we tend to see a signal potentially for PTEN deletions. Unfortunately, it was a negative study overall for all comers.
Alan H. Bryce, MD: How do you think through that issue of treating the primary [tumor]? Which patients are candidates for treatment through the primary [tumor]?
Tian Zhang, MD, MHS: That’s a great question. If Brian Chapin’s SWOG trial was open, I’d think about that. Usually, at the 6-month mark, those patients are getting randomized to prostatectomy, or there’s a cohort getting radiation to the primary [tumor] or going on systemic therapy. In my practice, if they are not study candidates, we’re often thinking about patients who have good responses at that 6- or 12-month mark in terms of their PSA drop and the radiographic findings. To be honest, I’m biased. I’m married to a radiation oncologist, so I’m a bit more aggressive in thinking about radiating the primary [tumor] if that’s the bulk of the disease and thinking about cytoreduction.
Alan H. Bryce, MD: Dr Lowentritt, as a urologist, how do you think through treating the primary [tumor] in a patient with metastatic disease?
Benjamin H. Lowentritt, MD, FACS: The encouraging data that suggest there’s an overall survival benefit for our patients with oligometastatic disease are eye-opening. As we start to think more about survival, urologists have historically thought about surgical outcomes, positive margins, lymph node disease, and lack of cure—when we were no longer treating patients if we thought we couldn’t get all the disease out. We’re coming full circle in understanding the real role for treating the primary and maybe treating some of the oligometastases, which is very attractive for surgeons—it’s “Let’s go after everything.” I appreciate what Dr Zhang said: that’s an aggressive approach. Let’s not be unreasonable. Let’s not do something that’s not going to help the patient. We have some emerging data that say it might; that’s great.
Although this patient comes in and has a CT scan, I’m curious if anyone would do further staging at this point with PSMA [prostate-specific membrane antigen]–PET [positron emission tomography]. How confident are we? Studies were done with conventional imaging, but if we’re going to start treating metastatic disease, should we be getting better imaging up front to understand the burden? Or should we just treat what we can see and treat it more when we see more? That approach is very interesting. It’s going to emerge through the variety of studies being done. Treating of the primary [tumor], especially with radiation, is very attractive. We’ll see what the surgery studies show as well. We talk about introducing adverse effects, and the introduction of incontinence is something we’d like to avoid whenever possible. But if we see good outcomes and patients seem to recover fairly well with their continence, they’re good surgical candidates. I’m excited to see what these studies show.
Alan H. Bryce, MD: Dr Petrylak, how do you think about PSMA-PET imaging for patients with hormone-sensitive prostate cancer? How do you assess and categorize a patient with disease that’s there only on the PSMA-PET?
Daniel P. Petrylak, MD: That’s a big problem because we don’t have any data to tell us how to treat that patient. I still do conventional imaging on these patients. If that’s negative, then I’d want to do a PSMA-PET scan. I base my treatment decisions on what’s known and what the conventional imaging is. The situations where PSMA-PET is useful clearly would be for patients with nonmetastatic disease. We try to attack the co-metastases and then, if you’re using this as a way to get a patient treated with lutetium-17- PSMA. But do you start radiating some of these other oligometastatic sites? You have to be very careful about false positives with PSMA testing, particularly in ribs, as well as in iliac lymph nodes. That has to be balanced against a patient’s clinical picture.
Alan H. Bryce, MD: Very fair.
Transcript edited for clarity.
