Metformin Active Surveillance Trial in Low-Risk Prostate Cancer
Metformin did not significantly reduce the risk of disease progression compared with active surveillance in patients with low-risk prostate cancer.
Long-term androgen deprivation therapy (ADT) improves survival in men with high-risk localized prostate cancer (PCa) receiving radiotherapy (RT). Predictive biomarkers are needed to guide ADT duration.
A multimodal artificial intelligence (MMAI)???derived predictive biomarker was trained for long-term (LT) versus short-term (ST) ADT using pretreatment digital prostate biopsy images and clinical data (age, prostate-specific antigen, Gleason, and T stage) from six NRG Oncology phase III randomized radiotherapy trials. The novel MMAI-derived biomarker was developed to predict the differential benefit of LT-ADT on the primary end point, distant metastasis (DM). MMAI predictive utility was validated on a seventh randomized trial, RTOG 9202 (N = 1,192), which randomly assigned men to RT + ST-ADT (4 months) versus RT + LT-ADT (28 months). Fine-Gray and cumulative incidence analyses for DM, and secondarily, death with DM, were performed. Deaths without DM were treated as competing risks.
In the validation cohort (median follow-up, 17.2 years), LT-ADT significantly improved DM from 26% to 17% (subdistribution hazard ratio [sHR], 0.64 [95% CI, 0.50 to 0.82], P < .001). A significant biomarker-treatment predictive interaction was observed (P = .04) for DM, whereby MMAI biomarker???positive men (n = 785, 66%) had reduced DM with LT-ADT versus ST-ADT (sHR, 0.55 [95% CI, 0.41 to 0.73], P < .001), whereas no treatment benefit was observed for MMAI biomarker???negative men (n = 407; sHR, 1.06 [95% CI, 0.61 to 1.84], P = .84). The estimated 15-year DM risk difference between RT + LT-ADT and RT + ST-ADT was 14% in MMAI biomarker???positive men and 0% in MMAI biomarker???negative men. The MMAI biomarker was also prognostic for DM, irrespective of treatment (sHR, 2.35 [95% CI, 1.72 to 3.19], P < .001).
To our knowledge, the MMAI model is the first validated predictive biomarker to guide ADT duration with RT in localized/locally advanced PCa. Approximately one third of men with high-risk PCa could safely be spared the additional 24 months of ADT and the associated morbidity.
Metformin did not significantly reduce the risk of disease progression compared with active surveillance in patients with low-risk prostate cancer.
For our radiation oncology colleagues, the addition of PSMA-directed therapy prior to stereotactic body radiation therapy (SBRT) improved progression-free survival (PFS) in patients with oligometastatic prostate cancer. Two cycles of PSMA-directed therapy were administered before SBRT.
A 13% reduction in mortality was observed in the screening group, with an improved harm-benefit ratio. For every 456 men screened, one prostate cancer death was prevented. It is an easy and inexpensive test, though concerns remain regarding unnecessary biopsies and overtreatment.
Pasritamig was administered to patients who had received a median of four prior lines of systemic therapy. It was well tolerated, with manageable adverse events, making it suitable for outpatient administration. The treatment showed a median radiographic progression-free survival of 7.85 months, and 14 out of 33 participants achieved a ≥50% reduction in baseline PSA levels. So, stay tuned.
In patients with localized prostate cancer, predominantly low-risk and intermediate-risk disease, the long-term update reveals 13-year outcomes. Treatment failure occurred less frequently in men undergoing HIMRT (n = 13) compared with those undergoing CIMRT.