Another fine MedPage Today review of a study, this one out of Milan, that reports a benefit to adding ADT to SBRT. The unanswered question would still seem to be the "what, when, and how much" ADT should be used for best benefit. NPfisherman (aka Dangerous Dave) has several past n=1 posts on this topic, one of which linked a research paper I forwarded to him via PM (Androgen Flare after LHRH Initiation Is the Side Effect That Makes Most of the Beneficial Effect When It Coincides with Radiation Therapy for Prostate Cancer). NP's most relevant FPC posts and the above referenced paper are linked at the end of this post.
As one who questions the QOL risk/benefits of long(er)-term SOC-ADT in general, I would likely choose a short-term ADT "flush" as described in the research listed above, as the objective of introducing mitosis for the RT period would seem to be efficiently achieved with that treatment approach with minimal-to-no impacts to QOL & min/no risk of contributing to CR-status. Regardless of my opinion, these various approaches should surely be discussed with one's RO before starting any SBRT treatment program.
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Study of Oligorecurrent Prostate Cancer Finds Winning Combination - Adding a short course of androgen deprivation to SBRT cut risk of disease progression in half, MedPage Today, Oncology/Hematology > Prostate Cancer, by Mike Bassett, Staff Writer, March 5, 2025
Key Takeaways
Addition of 6 months of androgen deprivation therapy to stereotactic body radiotherapy more than doubled PFS in hormone-sensitive oligorecurrent prostate cancer.
Nearly all patients treated with the combination achieved testosterone recovery at 1 year.
Certain subgroups may still derive similar benefit from stereotactic body radiotherapy alone.
A short course of androgen deprivation therapy (ADT) added to stereotactic body radiotherapy (SBRT) halved the risk of disease progression or death in patients with metachronous oligometastatic hormone-sensitive prostate cancer, a phase II study showed.
Median clinical progression-free survival (PFS) doubled from 15.1 months with SBRT alone to 32.2 months with the addition of 6 months of ADT (HR 0.43, 95% CI 0.26-0.72, P=0.0010), reported Barbara Alicja Jereczek-Fossa, MD, PhD, of the European Institute of Oncology in Milan, and colleagues.
Meanwhile, median biochemical PFS improved from 12.6 months to 26.8 months, respectively (HR 0.40, 95% CI 0.24-0.66, P=0.0002), according to findings detailed in Lancet Oncologyopens in a new tab or window.
"To the best of our knowledge, our study represents the first randomized effort to report the superiority, in terms of clinical progression-free survival, of SBRT and a [short course of ADT] compared with SBRT alone in metachronous oligorecurrent hormone-sensitive prostate cancer," wrote Jereczek-Fossa and co-authors.
"Considering that almost all patients in the combined treatment group achieved testosterone recovery at 1 year, the results support that this short term (intermittent) combined approach is an optimal option in selected patients with metachronous oligorecurrent hormone-sensitive prostate cancer," the research team added.
They emphasized "the importance of patient selection in treatment decisions" as a significant PFS advantage with ADT was not observed in those with a prostate-specific membrane antigen (PSA) concentration of 0-2 ng/mL, a PSA doubling time of more than 3 months, and M1a disease stage at baseline, along with patients whose time from first curative treatment to SBRT was more than 43 months.
"These data demonstrate that, perhaps as expected, adding a short course of ADT to metastasis-directed therapy [MDT] improves clinical progression-free survival," wrote Amar Kishan, MD, and Luca Valle, MD, both of the University of California Los Angeles, in a commentary accompanying the study.
"The data also suggest that this effect might be mediated primarily by suppressing occult disease rather than by eradicating it. Although physician-scored toxicity might be modest, the known effect of ADT on quality of life (which was not reported) can be substantial," they added. "Thus, the decision to add short-course ADT to MDT should still involve a detailed discussion of risks and benefits between patients and physicians."
The RADIOSA study from Jereczek-Fossa and colleagues was an open-label phase II trial conducted at the IRCCS European Institute of Oncology in Milan. The study randomized 105 adults to either SBRT alone (30 Gy in three fractions every other day or equivalent regimens depending on disease location) or in combination with 6 months of ADT.
Patients were eligible if they had an initial diagnosis of adenocarcinoma of the prostate, biochemical progression after radical local prostate treatment, nodal relapse in the pelvis, extra-regional nodal relapse, bone metastases at next-generation imaging with a maximum of three lesions, good performance status.
Participants had a median age of 70 years; race and ethnicity data were not collected. Most patients (64%) presented with one oligometastasis at enrollment, 26% with two, and 10% with three oligometastatic lesions.
The study's primary endpoint was clinical PFS, defined as the time from randomization until the presence of new local, regional, or distant metastatic lesions at staging examination, or death from any cause. Secondary endpoints included overall survival (OS) and biochemical PFS, among others.
OS was immature at the time of analysis, with post-hoc analysis showing 1- and 2-year rates of 100% and 95%, respectively, for the overall study population.
Regarding safety, one grade 3 adverse event (AE) occurred in one patient in the combination group, a left ureter stenosis. In addition, one patient in the SBRT alone group reported a gastrointestinal acute grade 1 toxicity. Both were resolved at the last follow-up.
For ADT-related toxicity, 43% in the combination group reported grade 1 AEs, the most common of which were hot flushes, reported in all of the patients reporting an AE. Other AEs reported in patients in the combination group related to ADT were asthenia in 16%, insomnia in 8%, and muscular pain in 4%.
author Mike Bassett is a staff writer focusing on oncology and hematology. He is based in Massachusetts.
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MedPage Article can be found here:
medpagetoday.com/hematology...
The Lancet paper here (abstract only - Note that via their access to the full papers, authors, and associated commentaries, these expert curated MedPage articles/reviews provide valuable patient information. This is more-so the case when these papers and commentaries are behind paywalls - as they very frequently are.
thelancet.com/journals/lano...
And the study's accompanying commentary is here (abstract only):
thelancet.com/journals/lano...
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Finally, here are the links to NP's pre/post SBRT treatment posts from ~3 years back:
Pre SBRT:
healthunlocked.com/fight-pr...
Post SBRT:
healthunlocked.com/fight-pr......
And to the paper I forwarded to him:
pmc.ncbi.nlm.nih.gov/articl...
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Stay S&W, Ciao - cujoe
EMBARK Study: Enzalutamide +/- ADT
Phase 2 trial: adaptive ADT for metastatic castration sensitive prostate cancer