867P - Multi-institutional evaluation of therapeutic management for oligometastatic cancer prostate recurrence with choline-PET/CT

Abstract

BackgroundCholine Positron Emission Tomography – Computed Tomography (Choline PET/CT) allows for the diagnosis of oligometastatic (OM) Prostate Cancer (PCa) recurrence that could be treated with a curative intent. The aim of the study was to evaluate the different therapeutic approaches and outcomes for first OM recurrence. MethodsThis multi-institutional, retrospective study included patients with a hormone-sensitive biochemical PCa recurrence after an initial curative local treatment, and with at least 1 to 5 Choline PET/CT-diagnosed metastatic lesions. Primary endpoint was Biochemical Recurrence Free Survival (BRFS). Secondary endpoints were Metastatic Recurrence-Free Survival (MRFS) and Androgen Deprivation Therapy-Free Survival (ADT-FS). ResultsBetween October 2012 and December 2016, 177 patients were included. Sixty-eight patients (38.4%) received an ADT alone, 72 (40.7%) received an External Beam Radiation Therapy (EBRT) – ADT association, 28 (15.8%) received an EBRT, 6 (3.4%) received a surgery, and 2 (1.1%) received a surgery with ADT. Median follow-up was 49 months [95%CI, 44.3-53.4]. Among patients who received non-standard treatment, 55% avoided long-term ADT. Grade 3 acute and late toxicities were rare (0.8% and 2.5% respectively). The median BRFS, MRFS and ADT-FS were 42 [95%CI, 37-51], 61 [95%CI, 45-81], and 53 [95%CI, 45-60] months, respectively. In multivariate analysis, concomitant ADT with MDT and "regional" EBRT combined with MDT significantly improved BRFS (p<0.0001 and p=0.0113 respectively) and MRFS (p=0.0005 and p=0.0013 respectively). In multivariate analysis, a PSA-doubling time of>3 months had a statistically significant positive impact on MRFS (p=0.0496) and ADT-FS (p=0.0007). The overall and disease specific survivals were 87% and 97% respectively at 5 years. The median incidence of castration resistant PCa was 80 months. ConclusionsIn patients with hormone-sensitive OM PCa recurrence after initial local treatment, BRFS and MRFS were significantly improved when concomitant ADT and "regional" EBRT were combined with MDT. Clinical trial identificationOMPPC-IPC 2018-059. Legal entity responsible for the studyInstitute Paoli-Calmettes. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.