Pelvic lymph node dissection can be safely omitted in men with a risk of nodal metastases ≤5% based on the Briganti nomogram: Validation of the EAU guidelines reccommendations for nodal dissection based on patient outcome

INTRODUCTION & OBJECTIVES: The updated EAU guidelines recommendations on the need for pelvic lymph node dissection (PLND) in prostate cancer indicate to omit PLND in patients with a risk of lymph node invasion (LNI) ≤5% based on the updated Briganti nomogram. Such recommendations have been given based on previous staging studies. However, whether PLND and its extent have no impact on cancer control in these patients with limited LNI risk has not been proven yet. MATERIAL & METHODS: This study included 1406 patients treated with radical prostatectomy with or without anatomically extended PLND between 1999 and 2012. All patients had a LNI predicted probability ≤5% according to the Briganti nomogram. All had complete clinical and follow-up data. Kaplan-Meier curves assessed the time to BCR, defined as two subsequent prostate-specific antigen values of 0.2 ng/ml or higher. Cox regression analyses tested the relationship between PLND status and biochemical recurrence (BCR) in the overall population. Likewise, Cox regression tested the relationship between the number of removed nodes and BCR in patients treated with PLND. Multivariable analyses were adjusted for all confounders, such as PSA, clinical stage, biopsy Gleason sum and percentage of positive cores. RESULTS: Mean patients age was 65.1 years (median: 66.0, range: 44.0-80.0). Mean and median follow-up times were 46.6 and 39.0 months, respectively. Most patients (87.7%) received PLND. Among these, the mean number of removed nodes was 15.1 (median: 14.0, range: 8-52). Overall, the 5- and 7-years BCR rates were 93.2% and 87.1%, respectively. These rates were respectively 90.6% and 90.6% in patients treated without PLND vs. 93.3% and 86.9% in patients treated with PLND (p=0.9). At multivariable analysis, PLND status was not a significant predictor of BCR risk (hazard ratio [HR]: 0.69, p=0.4). In patients treated with PLND, the number of removed nodes was not an independent predictor of BCR risk at univariable (HR: 1.00, p=0.9) and multivariable analyses (HR: 1.00, p=0.7). CONCLUSIONS: We report the first validation of the EAU guidelines recommendation on the need for PLND in prostate cancer based on post-operative patient outcome. Neither PLND nor its extent was significantly associated with improved cancer control in men with a LNI risk ≤5% according to the Briganti nomogram. Therefore, a PLND can be safely omitted in these patients.