Therapeutic sequencing in prostate cancer is an area of active discussion, although no consensus yet exists. At the 2024 Society of Nuclear Medicine & Molecular Imaging (SNMMI) Annual Meeting, experts discussed considerations in treatment sequencing. 

 Following these proceedings, featured expert Daniel P. Petrylak, MD, was interviewed by Conference Reporter Editor-in-Chief Tom Iarocci, MD. Dr Petrylak’s clinical perspectives on these findings are presented here.

There is not much consensus building in prostate cancer at this point. We need more molecular markers that can tell us what is going on in the individual patient. To select a treatment, we can use DNA damage repair mutations, and we hope to use AR mutations. We also use prostate-specific membrane antigen positron emission tomography (PSMA PET) scans. We do not yet have specific mutations that we can target like we have in lung cancer, for instance, and we are working toward improving that.

In terms of sequencing, I start with AR-targeted therapy and will discontinue it when patients need to go on to chemotherapy. It may make sense to use PSMA-targeted therapy after the first line of chemotherapy. An abstract presented at the 2024 SNMMI Annual Meeting during the session titled “Prostate Cancer – Focus on Therapy” evaluated the impact of PSMA-avid bone disease on treatment outcomes (abstract 241590). However, we do not routinely measure the total volume of bone involved with PSMA-avid disease because we do not know what the cutoffs are.

In terms of treatment response monitoring, there is certainly no consensus among contemporary guidelines. It is all a matter of opinion because we do not have enough evidence to fully back up recommendations. At my institution, we look at the individual patient, how they are doing, and what their side effects are. It is a multifactorial approach, and there are some cases in which you might use PSMA PET scans to monitor patients.

I think that the biggest area on which people should come together and find a consensus is with regard to DNA damage repair testing; this is needed for every patient. And once they have had chemotherapy, every patient should have a PSMA PET scan.