Top Line: Does metastasis directed therapy reduce the risk of progression in men receiving intermittent ADT for oligometastatic prostate cancer?
The Study: EXTEND is a randomized phase 2 trial testing if there is a benefit from metastasis directed therapy (MDT) for patients with oligometastatic cancer of various tumor types. In this prostate sub-study, 87 men with ≤5 oligometastatic prostate cancer who had been on at least 2 months of ADT were randomized to receive 6 more months of ADT with or without definitive radiation to all sites of disease. Most patients (72%) had received prior definitive treatment to the prostate, and about a quarter had fluciclovine PET for staging. After 6 months of ADT, patients were then given a break until progression. Biochemical progression was defined as a 25% increase in the PSA and at least 2.0 above nadir. The addition of MDT significantly reduced the rate of progression from 64% to 30%, and it prolonged median PFS from 15.8 months with ADT alone to not reached (median follow up 22 months). 60% of patients were off ADT long enough for their testosterone to recover to 150ng/dL or higher. Among these, MDT significantly prolonged median PFS with normal testosterone from 6.1 months to not reached. Finally, at 2 years, the incidence of failure at new sites was also reduced with MDT (33% v 41%).
TBL: Among men receiving intermittent ADT for oligometastatic prostate cancer MDT prolongs time to progression and also allows a subset of patients to enjoy significant time free of disease with a normal testosterone level. | Tang, JAMA Oncol 2023
The Study: EXTEND is a randomized phase 2 trial testing if there is a benefit from metastasis directed therapy (MDT) for patients with oligometastatic cancer of various tumor types. In this prostate sub-study, 87 men with ≤5 oligometastatic prostate cancer who had been on at least 2 months of ADT were randomized to receive 6 more months of ADT with or without definitive radiation to all sites of disease. Most patients (72%) had received prior definitive treatment to the prostate, and about a quarter had fluciclovine PET for staging. After 6 months of ADT, patients were then given a break until progression. Biochemical progression was defined as a 25% increase in the PSA and at least 2.0 above nadir. The addition of MDT significantly reduced the rate of progression from 64% to 30%, and it prolonged median PFS from 15.8 months with ADT alone to not reached (median follow up 22 months). 60% of patients were off ADT long enough for their testosterone to recover to 150ng/dL or higher. Among these, MDT significantly prolonged median PFS with normal testosterone from 6.1 months to not reached. Finally, at 2 years, the incidence of failure at new sites was also reduced with MDT (33% v 41%).
TBL: Among men receiving intermittent ADT for oligometastatic prostate cancer MDT prolongs time to progression and also allows a subset of patients to enjoy significant time free of disease with a normal testosterone level. | Tang, JAMA Oncol 2023