Indication for and extension of pelvic lymph node dissection during robot-assisted radical prostatectomy: an analysis of five European institutions

Abstract

Background: Several reports have shown that patients who undergo minimally invasive radical prostatectomy have a lower chance of undergoing pelvic lymph node dissection (PLND), irrespective of the disease characteristics.

Objective: We evaluated the rate and extension of PLND in patients who underwent robot-assisted radical prostatectomy (RARP). We tested the adherence of the indication for PLND to the European Association of Urology (EAU) guidelines.

Design, setting, and participants: Our study was a multi-institutional retrospective analysis of prospectively collected data on 2985 consecutive patients who underwent RARP at five high-volume European institutions. Patients were stratified according to preoperative cancer risk group.

Intervention: RARP.

Outcome measurements and statistical analysis: The rate and extent of PLND across different institutions were analyzed. Univariable and multivariable logistic regression models evaluated the association between preoperative variables and the probability of receiving PLND, as well as the presence of lymph node invasion (LNI). Finally, the probability of LNI was calculated for each patient, and the indication for PLND was compared with the EAU guidelines' indications.

Results and limitations: A lymph node dissection was performed in 1777 patients (59.7%; 34.5% of low-risk patients, 64.9% of intermediate-risk patients, and 91.2% of high-risk patients). These rates were different across institutions: 5.0-41.4% in low-risk patients (p<0.001), 31.3-81.4% in intermediate-risk patients (p<0.001), and 84.6-96.4% in high-risk patients (p=0.06). The mean and median number of nodes removed was 10.8, and 122 patients (4.1%) had nodal metastases. At multivariable analysis, the institution represented an independent predictor of PLND (p<0.001). Of patients with current indication for PLND (EAU guidelines), 77.8% actually received the procedure. Limitations were the retrospective study design with different pathologic assessment and lack of follow-up data.

Conclusions: PLND is performed in a high proportion of patients undergoing RARP in high-volume centers in Europe for whom the procedure is indicated by the EAU guidelines, but significant differences exist among institutions. An effort toward a more rigorous standardization of PLND is advocated.

Patient summary: In this paper, we investigated the indication for and extension of pelvic lymph node dissection (PLND) in different institutions in Europe. Despite PLND being widely performed, significant variations with regard to PLND do exist among different institutions. Therefore, a thrust toward more rigorous attention to PLND is advocated.

Keywords: Lymph nodes; Lymphadenectomy; Prostate cancer; Radical prostatectomy; Robotics.