MP34-12\u2003THE ROLE OF SALVAGE LYMPH NODE DISSECTION IN NON-METASTATIC CASTRATION-RESISTANT PROSTATE CANCER PATIENTS: A SINGLE CENTER EXPERIENCE

Abstract

INTRODUCTION AND OBJECTIVES: The standard of care for patients with nonmetastatic, castration-resistant prostate cancer (nmCRPCa) is androgen-deprivation therapy (ADT). Salvage lymph node dissection (sLND) may have a role in slowing disease progression and postpone the use of systemic therapies (SyS) in patients with lymph node (LN) only recurrence CRPCa. We aimed to evaluate oncologic outcomes of patients treated with sLND or SyS for nmCRPCa with nodal only recurrence. METHODS: 23 (51.1%) patients underwent sLND and 22 (48.9%) received SyS (ADT or chemotherapy) for LN-only CRPCa recurrence after radical prostatectomy (RP) detected at 11C-choline PET/CT (01/1990-01/2016). Biochemical recurrence (BCR) was defined as a PSA >0.2 ng/ml with an increased trend and radiological recurrence (RAR) was defined as a positive imaging study or biopsy proven metastasis after sLND or SyS. Kaplan-Meier method was used to assess time to BCR, RAR, and cancer-specific mortality (CSM). Predictors of BCR and RAR were assessed with Cox regression analyses. RESULTS: Median follow-up for the entire cohort was 49.3 mo [interquartile range: 27.5-64.3]. Groups did not differ in terms of Gleason score (GS), pathological stage (pT) at RP, PSA pre salvage treatment and number of positive LN at recurrence. Mean PSA reduction was significantly higher after sLND than SyS (62.8% vs. 17.7%; p=0.04). At follow up, 10 (22.2%) patients died from PCa, 34 (61.8%) had disease recurrence and 39 (86.7%) had BCR. The 5-yr CSM-free survival rates were 72.7% and 72.3% for sLND and SyS patients, respectively (p=0.08). There was a trend toward a longer median time to BCR [13.3 vs. 6 mo; p=0.1] and time to RAR [21.1 vs. 14.2 mo, p=0.09) in patients treated with sLND than SyS. Mean time to second-line SyS for disease progression was longer in the sLND group than SyS (66.1 vs. 43.3 mo; p=0.04). Univariable Cox regression analyses showed that PSA doubling time at recurrence (HR 0.57, p=0.025) and pT stage ≥3 at RP (HR 2.61, p=0.014) were associated with RAR. Age and PSA at nmCRPCa, number of positive LN, GS and sLND vs. SYS were not. None of the variables were associated with BCR. CONCLUSIONS: These preliminary findings show a potential role for sLND in delaying time to disease recurrence and the use of systemic therapies in nmCRPC patients as compared to SyS. PSA doubling time at recurrence and pT stage at RP were the only factors associated with RAR. Multicenter prospective studies with a larger cohort are needed to confirm our results. Source of Funding: none