MP22-14 DEFINITIVE THERAPY FOR MEN WITH NEWLY-DIAGNOSED OLIGOMETASTATIC PROSTATE CANCER: INITIAL SURGICAL OUTCOMES FROM A PHASE II STUDY

Abstract

Introduction & Objectives: Although men with newly-diagnosed oligometastatic prostate cancer have historically been treated with androgen deprivation therapy (ADT), emerging evidence suggests local treatment of the primary tumor may improve survival. Recent randomized trials have also demonstrated benefit from combination docetaxel with ADT for men with naive metastatic prostate cancer. The use of local consolidative treatment in conjunction with neoadjuvant chemo-hormonal therapy in this setting, however, has not previously been described. We present the initial surgical outcomes of a novel protocol. Material(s) and Method(s): A phase II study conducted at our institution began accruing patients in 2016. Men with newly-diagnosed synchronous oligometastatic prostate cancer (T1-4, N0-1, M1a-b) consisting of <0.1-5.1). Median operative time, blood loss, and length of hospitalization were 181 min (range, 116-230), 275 ml (range 100-1,800), and 1 day (range 1-3), respectively. Seven patients underwent open and seven underwent robot-assisted radical prostatectomy with a 7.1% peri-operative transfusion rate (1 patient) in the open group and none in the robotic group. One patient (7.1%) experienced a Clavien grade II complication (hematuria). The majority of men (10 patients, 71.4%) had >=ypT3a disease and 7 (50%) had positive surgical margins. Overall, lymph node dissection yielded a median of 13 nodes (range, 9-70), and 5 (35.7%) men were found to have lymph node metastases. Four patients (28.5%) have undergone adjuvant XRT and 5 (35.7%) have completed their SBRT, to date. Eight patients thus far have obtained post-treatment serum PSA levels, all of which are undetectable. Conclusion(s): The combination of neoadjuvant chemo-hormonal therapy with definitive local therapy and SBRT may redefine the treatment of oligometastatic prostate cancer and appears feasible based on initial surgical outcomes. Long-term safety, survival, and functional outcomes from this trial are forthcoming.