The effect of lymph node dissection on oncological outcomes in contemporary robotic salvage radical prostatectomy patients: a junior ERUS/YAU collaborative study

Purpose: Surgical features associated with better cancer-control outcomes are under investigation for salvage radical prostatectomy patients undergoing robotic approaches. Methods: The Junior ERUS/Young Academic Urologist Working Group in Robotics in Urology conducted a multicentric project to investigate the effect of lymph node dissection (LND) and pN stage on biochemical recurrence-free (BCR), metastases-free (MFS) and overall survival (OS) outcomes in 444 robotic salvage radical prostatectomy (s-RARP) patients. Results: Of all patients, 63% underwent LND with a median of eight removed lymph nodes. Patients without LND more frequently underwent initial focal therapy (60% vs. 37%) and harbored higher pathological Gleason score 8-10 (both p ≤ 0.02). In BCR analyses, no differences were observed between patients with vs. without LND with 24-months BCR-free survival rates of 74.8% vs. 73.6%. In OS analyses, better OS for LND patients (HR: 0,39, p = 0.049) was observed with 60-months OS rates of 81.3% vs. 92.1% for no LND vs. LND. Of LND patients. 16% harbored pN1 stage, which was associated with worse BCR-free survival (HR: 2.0,p = 0.025) with 60-months BCR-free survival rates of 63% for pN0 vs. 49.6% for pN1. In MFS analyses, no difference between both groups were observed. In OS analyses, the observed differences did not reach statistical significance with 60-months OS rates of 93.4% for pN0 vs. 84.7% for pN1. Conclusion: Rates of LND are relatively low in contemporary s-RARP patients and are more frequently performed in patients with worse characteristics. However, LND may be associated with better OS, while pN1 patients are associated with worse cancer-control outcomes.