New MD Anderson results from the Wolverine meta-study, a continuing meta-analysis of individual patient data from multiple randomized trials on oligometastatic PCa. UroToday Interview 3/3/25.
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Chad Tang discusses the WOLVERINE study, a meta-analysis of individual patient data from multiple randomized trials on oligometastatic prostate cancer. This collaborative effort pools data from STOMP, ORIOLE, ARTO, EXTEND, and COMET-SABR trials to evaluate metastasis-directed therapy. Results show significant improvements in progression-free survival, radiographic progression-free survival, and freedom from castration resistance. While overall survival shows a favorable trend, it does not reach statistical significance. The analysis adjusts for trial-level differences and examines various subgroups, finding consistent benefits regardless of ADT use, imaging modality (including PSMA PET), or number of metastases (up to five).
Biographies:
Chad Tang, MD, Associate Professor, Genitourinary Radiation Oncologist, The University of Texas MD Anderson Cancer Center, Houston, TX
Leslie Ballas, MD, Director, Hematologic/Bone Marrow Transplant/Cellular Therapies Disease Research Group, Cedars-Sinai Medical Center, Los Angeles, CA
Related Content:
ASCO GU 2025: World-Wide Oligometastatic Prostate Cancer (omPC) Meta-Analysis Leveraging Individual Patient Data (IPD) from Randomized Trials (WOLVERINE): An Analysis from the X-MET Collaboration
ASTRO 2024: Radiotherapy of the Primary Tumor and All Metastatic Lesions in Oligometastatic Prostate Cancer: 5-Year Results of Prolong Study
ASTRO 2023: Prostate Directed Radiation in the Oligometastatic Setting
Read the Full Video Transcript
Leslie Ballas: Hi, Thank you for joining us. Welcome to ASCO GU 2025. I'm Leslie Ballas, a radiation oncologist at Cedars-Sinai in Los Angeles.
I am lucky to be joined today by Doctor Chad Tang, a radiation oncologist at MD Anderson Cancer Center in Houston. He is going to talk to us today about his abstract, "World-Wide Oligometastatic Prostate Cancer Meta-Analysis Leveraging Individual Patient Data from Randomized Trials," also known as the WOLVERINE study. Doctor Tang, thank you so much for joining us today. Why don't you tell me a little bit about this abstract?
Chad Tang: Thank you, Doctor Ballas. So this abstract is born of a collaboration between me and multiple other centers and investigators who have run randomized studies looking at oligometastatic disease. And it is meant to collaborate and pool all the individual patient data across these different studies. And we're focusing specifically on the oligometastatic prostate cohort, which has by far the most number of studies. And our goal was to assess the effect of metastasis-directed therapy, mainly with radiation therapy, for different endpoints across these studies, and also look at subgroups to see if there's any benefits that persist or are better than others.
Leslie Ballas: And what did you find?
Chad Tang: Yeah, so we found, strikingly, an extremely good outcome associated with metastasis-directed therapy. The main endpoint that a lot of studies are looking at is progression-free survival. But beyond that, we looked at radiographic progression-free survival, freedom from castration resistance-free survival. And that was also significantly improved. And in terms of the big endpoint, overall survival, although it wasn't significant at a p-value of 0.05, it was quite favorable, suggesting that, across these later endpoints—which haven't been as reported—metastasis-directed therapy is beneficial in oligometastatic prostate cancer patients.
Leslie Ballas: You took individual patient data from STOMP, ORIOLE, ARTO, your own EXTEND basket trial. How did you handle the different use of ADT across these trials? In your own EXTEND data, you looked at biochemical progression-free survival, or you call it eugonadal biochemical progression-free survival. Did you look at the same endpoint here, or was it biochemical progression-free survival regardless of ADT time?
Chad Tang: Yeah, that is a good question. So one other thing is we also have COMET-SABR in the analysis.
Leslie Ballas: Oh, thank you.
Chad Tang: That's only the prostate patients which we pulled out from that. But a couple of points—The first point is, when we did the analysis, the use of ADT, as you mentioned, is actually very specific to the trial. So when we did all our analysis, we did a trial-level adjustment to account for that difference. And in addition, we also looked at subgroup analysis in patients who had ADT, who didn't have ADT, and who had second-generation ADT. And the effects persist across.
Progression-free survival, we harmonized the definition across all studies. And this was a combination of either biochemical progression regardless of eugonad status, radiographic progression, clinical progression, or death. So it could be any of these endpoints, which is consistent relatively across the different studies.
Leslie Ballas: How did you evaluate the radiation dosing across trials?
Chad Tang: Yeah, so generally across all studies, the radiation dosing was definitive in intent and usually ablative in delivery. So we haven't looked at, exactly, the dosing question. But given the local control across all the studies, it's really high—90% plus local control. We generally feel that the dosing was sufficient to control at least localized disease.
Leslie Ballas: How do you incorporate your data in the era of PSMA? Not all of these studies use PSMA in their radiographic progression-free survival.
Chad Tang: Yeah, so an excellent question. These studies span a couple of different eras. It just so happens to be we're in interesting times in prostate cancer. So we did have studies where staging was done with PSMA PET, some with choline PET, some with standard CT, some with fluciclovine PET.
So we did parse that out in the subgroup analysis. And in especially our PSMA PET population, the benefit for metastasis-directed therapy was actually quite good. In fact, it may even be a little bit numerically better than the other imaging modalities. So I think, regardless of what you're imaging with, you're going to benefit with MDT.
Leslie Ballas: Remind me, were the number of mets treated in each of the trials consistent? Oligometastatic oligoprogressive is in the ARTO trial. You know, oftentimes, it's defined as 1 to 3, 1 to 5. And I think there was some variability across trials. How did you handle that?
Chad Tang: Yeah, so some trials are 1 to 3, and some trials are 1 to 5. But generally, they're all less than 5. So we would say we kept the scope less than 5 mets in this analysis.
We did look at subgroups in terms of the 1 to 2, 1 to 3, and 4 to 5. We just cut it in all different ways. And across different subgroups, at least for the PFS—which is the endpoint where we have the most power to look at—there was still a maintenance and benefit for MDT.
Leslie Ballas: Well, congratulations on this collaborative work. Is there anything else you want to tell us about it?
Chad Tang: Yeah, so X-MET is an ongoing, we think, relatively egalitarian collaboration between investigators who are interested in learning more about metastasis-directed therapy. So we encourage all investigators who have randomized trials to contribute. We have meetings. We discuss different analyses. So we'd be more than welcome to welcome new studies into this mix.
Leslie Ballas: Thank you again for joining us today.
Chad Tang: Thank you.
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UroToday link:
BCR May Not Be a Strong Surrogate End Point for Prostate Cancer Survival
