Alan Bryce, MD: Dr Posadas, let’s switch back to you here. What are your monitoring strategies for patients with nmCRPC [non-metastatic castration-resistant prostate cancer]? How do you follow them?

Edwin Posadas, MD: I’m just thinking that question falls so nicely from what Dr [Benjamin] Lowentritt [MD, FACS] was saying because I follow patients in this disease setting for 2 things. One is for disease progression; I think most of us will say in the non-metastatic space, given the long natural history, you can probably get away with doing a disease progression assessment every 3 months, at least by PSA [prostate-specific antigen]. To Dr Lowentritt’s point, PSA is great. It has its flaws, but every other tumor system wants a PSA to have the problems that we have but I will still countercheck with imaging and I may bias that depending upon the molecular phenotype. If I know, for example, they have tumor suppressor losses and a disposition to a more plastic biology, I will probably image them twice a year for fear that they will stop producing PSA and move in another direction without me checking. I don’t want to miss that event, but as Dr Lowentritt said, they’re supposedly going to live for a long time. They viewed their lives through PSA. I must ensure that we’re not going to hit any of the road bumps. Dr Bryce, you mentioned it nicely when you were recounting your experience. I had a patient that I put on an ARSI [androgen receptor signaling inhibitor] and nonsteroidal antiandrogen and within 2 weeks he was falling and ended up in the emergency [department] because of the CNS [central nervous system] penetration of that agent. I switched him over to an alternative agent, and his brain fog cleared and he felt much better. When I treat a nonmetastatic patient, I will do a quick early check to look for liver toxicity, for CNS issues that are already manifesting, especially in my older patients, because as much as we were joking about the wibbly wobblies, false correlate with poor outcomes in prostate cancer, and if I’m getting the sense that there’s gait instability or any neurologic issues that are at hand, I have to think twice about whether that’s the right drug to use or whether I’m being too aggressive in that particular setting. There are patient factors that will filter into that, things like cardiac history because as you intensify AR [androgen receptor] blockade, you impact their cardiovascular risk. These are all older men and that’s still the leading killer of men over the age of 50. As oncologists, we have an obligation to make sure our patients are informed about that and participate in that education.

Alan Bryce, MD: Fair. I agree with you completely.

Transcript edited for clarity.