Login to Access Video or Poster Abstract: MP53-12
Sources of Funding: None

Introduction

There are several retrospective series regarding metastasis-directed therapy (MDT), in the form of either salvage lymphadenectomy (sPLND) or stereotactic body radiotherapy (SBRT), to PET-positive lymph node recurrences after initial radical prostatectomy (RP) and postoperative radiotherapy (PORT). However, these studies are single arm studies without a control group of patients not receiving MDT, which is still considered standard of care (SOC). We pooled data from 5 institutions and performed a retrospective case-control study to assess the influence of MDT to pelvic lymph node metastasis on cancer-specific survival (CSS).

Methods

The SOC-cohort consisted of 2270 men who underwent RP+PORT (adjuvant or salvage) between 1996-2013 at a single institution (Hamburg) and experienced subsequent biochemical failure managed with systemic treatment administered at physicians&[prime] discretion. The MDT-cohort comprised 227 patients treated with RP+PORT between 1996-2013 who experienced a biochemical recurrence (BCR) followed by a Choline or PSMA PET-detected nodal recurrence. This recurrence was managed with either sPLND (n= 150) or SBRT (n= 77). In case of further systemic progression, systemic treatment was administered at physicians&[prime] discretion. Disease characteristics and the impact of MDT on cancer-specific survival (CSS) was assessed using Cox proportional hazard models. CSS was measured from time of BCR following RP+PORT. A propensity-score matched pair analysis between SOC and MDT patients was performed based on known prognostic factors at initial diagnosis (PSA prior to RP, year of RP, RP Gleason Grade, age, pN-status and pT stage).

Results

In total, 384 were matched (187:187) with a median follow-up of 64.2 months. Type of treatment (SOC vs. MDT), age at RP, RP Gleason Grade and margin status were significantly associated with cancer-specific survival in multivariate analysis (all p<0.05). After matched-pair analysis, 10 year CSS was 79.4% (95% CI 66.5-88.2)for SOC and 98.8% (95% CI 91.4-98.8) for MDT(p= 0.002).

Conclusions

MDT to pelvic nodal recurrences of PCa is associated with improved CSS compared to SOC. These data should be considered hypothesis-generating and inform future randomized trials in this setting.

Funding

None