EAU 2020: Five Things We Have Learned About Kidney Cancer

(UroToday.com) Karim Bensala, MD, Ph.D., began his talk discussing the evolution of small renal masses (SRMs). The DISSRM registry has shown that 80% of SRMs have a less than 0.5 cm/year growth rate, and 30% remain stable1 (Figure 1). 35% of SRMs do not grow at all, and there is no correlation between low growth rate and initial tumor diameter.


Figure 1 – SRM growth rate in active surveillance patients:

SRMGrowthRate.png
Data from a prospective registry2 have also shown that 55% of active surveillance patients have a primary intervention, 45% remain on active surveillance, and 9% had delayed intervention with a 5 years cancer-specific survival rate of 99% vs. 100%. According to the EAU guidelines, active surveillance should be offered to frail and/or comorbid patients with SRM.

When assessing larger tumors (T1b or T2), a large meta-analysis of 21 case-controlled studies with over 11,000 patients demonstrated that the relative risk was 0.65, p=0.03, favoring partial nephrectomy over radical nephrectomy.3 Partial nephrectomy also benefits in improved renal function. In 2020, there is no doubt that partial nephrectomy is the best option to treat SRMs.

One of the ways to refine the actual surgery is to make it less invasive, and for laparoscopy, it was shown that 800 cases are needed to achieve expertise, while with the robot, the number of cases is considerably lower. All over the world, minimally invasive, and specifically, robotic procedures are on the rise (Figure 2).

 Figure 2 – Partial nephrectomy epidemiology: PartialNephrecotmyepidemiology.png

There have been many studies comparing open to robotic partial nephrectomy (33 studies, with 4431 cases vs. 4675 cases), and robotic partial nephrectomy vs. laparoscopic partial nephrectomy (51 studies with 4289 cases vs. 3824 cases).4 This meta-analysis assessing these comparisons demonstrated the following differences, as shown in table 2 and table 3. 

Table 2 – Differences between robotic and open partial nephrectomy:
Diff_betwee_Robotic_Open_Nephrectomy.png

Table 3 – Differences between robotic and laparoscopic partial nephrectomy Robotic_laproscopic_nephrectomy.png

Other methods to improve outcomes of partial nephrectomy is to improve renal preservation. This can be done by improving renal ischemia time, as has been shown In a study comparing GFR when the ischemia time was over and under 25 minutes5 (Figure 3). In a large meta-analysis of 29 studies, the two most important factors affecting renal function in partial nephrectomy were preoperative renal function and the proportion of spared renal parenchyma.6

Figure 3 – Comparison of ischemia time and its effect on GFR:

 Ischemiatime_Effect_GFR.png

Other renal sparing techniques such as zero ischemia time, selective clamping, non-clamping, and no parenchymal suture, have an unclear effect yet on the postoperative renal function. They could be associated with fewer complications, but currently, they are not recommended due to a lack of sufficient evidence.

Presented by: Karim Bensala, MD, Ph.D., University of Rennes, France

Written by Hanan Goldberg, MD, MSc., Urology Department, SUNY Upstate Medical University, Syracuse, NY, USA, Twitter: @GoldbergHanan at the Virtual 2020 EAU Annual Meeting #EAU20, July 17-19, 2020.

References:

  1. Uzosike AC, Patel HD, Alam R, et al. Growth Kinetics of Small Renal Masses on Active Surveillance: Variability and Results from the DISSRM Registry. The Journal of urology 2018; 199(3): 641-8.
  2. Pierorazio PM, Johnson MH, Ball MW, et al. Five-year analysis of a multi-institutional prospective clinical trial of delayed intervention and surveillance for small renal masses: the DISSRM registry. European urology 2015; 68(3): 408-15.
  3. Mir MC, Derweesh I, Porpiglia F, Zargar H, Mottrie A, Autorino R. Partial Nephrectomy Versus Radical Nephrectomy for Clinical T1b and T2 Renal Tumors: A Systematic Review and Meta-analysis of Comparative Studies. European urology 2017; 71(4): 606-17.
  4. Cacciamani GE, Medina LG, Gill T, et al. Impact of Surgical Factors on Robotic Partial Nephrectomy Outcomes: Comprehensive Systematic Review and Meta-Analysis. The Journal of urology 2018; 200(2): 258-74.
  5. Thompson RH, Lane BR, Lohse CM, et al. Comparison of warm ischemia versus no ischemia during partial nephrectomy on a solitary kidney. European urology 2010; 58(3): 331-6.
  6. Rod X, Peyronnet B, Seisen T, et al. Impact of ischaemia time on renal function after partial nephrectomy: a systematic review. BJU international 2016; 118(5): 692-705.