The power of PSMA.

Top Line: We first heard the impressive results of the ORIOLE trial in abstract form at ASTRO 2020.

The Study: The full manuscript is now hot off the press. As a reminder, 54 patients with recurrent (i.e., after definitive surgery or radiation), hormone-sensitive, oligometastatic (i.e., 1-3 asymptomatic mets none larger than 5 cm) prostate cancer were randomized 2:1 to stereotactic body radiation (SBRT) to all CT-visible sites versus observation. Again, the primary endpoint of rate of progression at 6 months was drastically improved from 11/18 (61%) with observation to only 7/36 (19%) with SBRT. The obvious question here: what kind of control is observation for new mets? While the authors recognize “the approach is controversial, many men are interested in avoiding the unpleasant adverse effects and potential health risks of ADT for as long as is reasonable.” This is somewhat unfortunate given the anticipated hesitancy of med oncs to extrapolate this data to the vast majority of patients treated with some form of systemic therapy—they are hormone-sensitive, after all. An important point here is that there were no grade 3+ adverse events with SBRT, suggesting this could potentially offer a patient-preferred, effective first-line treatment option. Finally, an important component was exploring the added utility of PSMA imaging—all patients had it but rad oncs were blinded to the results. Therefore 16/36 in the SBRT arm had untreated PSMA mets, among whom 6 (38%) progressed by 6 months compared to only 1 (5%) who had no untreated PSMA mets.

TBL: SBRT to all (per PSMA) new prostate cancer oligomets is an effective and well-tolerated way to improve oncologic outcomes, meriting a larger phase 3 trial that will hopefully allow dealer’s choice systemic therapy. | Phillips, JAMA Oncol 2020