Introduction: There are no clear recommendations for the management of patients with lymph node invasion discovered during radical prostatectomy for prostate cancer (PCa). Adequate risk stratification could personalize post-surgical adjuvant treatment. Our objective was to identify predictive factors for biochemical relapse (BCR) in patients with lymph node (LN) invasion at the time of radical prostatectomy(RP).

Materials and methods: Patients who underwent RP for high-risk PCa with LN invasion in two academic centres between 2008 and 2019 were included. Patients with metastatic disease or extrapelvic LN involvement were excluded. Following data were collected retrospectively: age, preoperative prostate-specific antigen level, Gleason score, clinical and pathological stage, number of metastatic LN and LN density. Outcome was BCR during follow-up. BCR-free survival was assessed by Kaplan-Meier method and its association with relevant variables was determined with log-rank test.

Results: Twenty-six patients were included. Median (IQR) age, PSA and follow-up were 64.5 years (55-78), 9.2ng/mL (4.4-20) and 16.1 months (6-27.5), respectively. Twenty patients (77%) had BCR after surgery, accounting for 24-month BCR-free survival of 65%. Patients with LN density > 15% had better survival rates than those with ≤ 15% (40% vs. 0%, respectively, at 24 months; P=0.06) without reaching significance. Cox proportional Hazards analysis could not evidence predictive factors of BCR free-survival.

Conclusions: LN density seemed associated with BCR-free survival within patients with high-risk PCa and positive LN at RP. However, extraprostatic extension, number of positive LN and positive surgical margins were not independent risk factors for BCR. Larger prospective studies with centralized pathological reviews are needed.

Level of proof: 3.