EAU 2019: Mid-Term Oncologic and Functional Outcomes of Endoscopic Robot-Assisted Simple Enucleation for Renal Tumors: Results from a Tertiary Referral Centre

Barcelona, Spain (UroToday.com) In this abstract, the authors from a single institution in Italy provide their midterm evaluation (oncologic and functional) of Endoscopic robot-assisted simple enucleation (ERASE) procedures for patients with smaller renal masses.

There has long been a debate regarding the efficacy of enucleation vs. formal partial nephrectomy, with the main technical difference being the inclusion of a rim of normal renal parenchyma with the excised specimen. Concerns regarding both techniques include the rates of positive surgical margins and the effect of renal function (nephron-sparing). 

ERASE is a robotic approach to enucleation of renal masses. This technique has been previously described by Minervini et al. (Surg Endoscopy 2015). In this manuscript, the authors provide prospectively collected data on 645 patients who underwent robotic partial nephrectomy between 2011 and 2016. Outcomes included renal function (RF) injury, described as >= 20% drop in eGFR from baseline, local recurrence (LR), defined as any recurrence localized in the ipsilateral kidney, and systemic recurrence (SR), defined as any other recurrence distant from ipsilateral kidney, including in ipsi- or contralateral retroperitoneal lymph nodes, in contralateral kidney or in distant organs. Resection technique was reported by the surface-intermediate-base technique. This study aims to assess mid-term oncologic and functional outcomes.

Of the 645 patients who underwent robotic partial nephrectomy, 483 has a SIB score of 0-1, which correlates to having had an ERASE (enucleation). It is unclear if the intent is always an ERASE going in, or if this is usually determined retrospectively through the SIB score. No information on demographics was provided nor was a Table 1 available on the poster.

Looking at RF drop, a >20% drop was noted in 178 (37%) of patients at POD #3. At a median functional follow-up at 3 years, 91 patients (18.9%) had a significant RF drop. Albeit, the authors use a definition of RF injury not consistent with prior studies – usually, the drops correlate with CKD stage changes. When looking at predictors of RF loss at POD#3, older age and higher PADUA scores were predictors of worse RF loss. When looking at predictors of RF loss at 3 years, older age, female gender, pre-operative eGFR, and higher BMI scores were predictors of worse RF loss. 

On final pathology, only 68.1% had a malignancy in the tumor – this seems quite low and somewhat concerning about their selection for patients for surgery. Positive surgical margins were noted in 2.7% of those cases with malignancy. 

With a median follow-up of 46 months (36-70 months IQR), 1.9% experienced LR and 1.5% experienced SR. Only 0.8% had both. 5-year RFS was 94.2%. Patients with PSM and high-grade histology were associated with greater recurrence. 

So, while the authors claim excellent mid-term (~4-year) oncologic and functional outcomes, not a lot of data was provided regarding demographics and the details of the study, making it a bit hard to make a fair judgment of the results. 

Presented by: Riccardo Tellini, MD, Department of Urology, University of Florence, Careggi Hospital, Florence, Italy

Written by: Thenappan Chandrasekar, MD (Clinical Instructor, Thomas Jefferson University) (twitter: @tchandra_uromd, @JEFFUrology) at the 34th European Association of Urology (EAU 2019) #EAU19, conference in Barcelona, Spain, March 15-19, 2019.