ERUS 2018: Best Papers in Kidney Cancer

Marseille, France (UroToday.com) Dr. Canda presented a summary of some important papers in robotic surgery for the treatment of kidney cancer. The first topic discussed was zero ischemia. Zero ischemia has a proposed advantage of avoiding any negative impact on postoperative renal function. The conventional robotic-assisted partial nephrectomy (RAPN) with clamping of the renal artery may negatively impact postoperative renal function, which may be detrimental, especially in patients with chronic renal disease. The first relevant paper presented: “Every minute counts when the renal hilum is clamped during partial nephrectomy”1 included 362 patients with a single kidney who underwent open and laparoscopic partial nephrectomy (PN) with warm ischemia with hilar clamping. From 226 patients with a preoperative GFR of >30, 17% developed new-onset chronic kidney disease and 19% developed acute renal failure. A cut point of 25 minutes provided the best distinction, with worse outcomes seen with every additional minute of warm ischemia.

Another important relevant paper was published in the BJUI in 2015: “Evaluation of functional outcomes after laparoscopic partial nephrectomy using renal scintigraphy: clamped vs. clampless technique”2 demonstrated in a multivariable analysis that the lower the baseline values of the split renal function and estimated renal plasmatic flow, the poorer the postoperative functional outcome. The patients who benefited the most from a clampless approach were those with the poorest baseline renal function. A meta-analysis evaluating clampless vs. complete hilar control in PN demonstrated that with appropriate patient selection clampless PN offers comparable outcomes to those of clamped PN. These outcomes include perioperative safety, equivalent oncological outcomes, and superior long-term renal function preservation.3 Lastly, a paper comparing RAPN with different clamping techniques (clampless, selective clamp, and main artery clamping) demonstrated no significant differences in transfusion rates, positive surgical margin rates, complications, recurrence, and mortality rates between the various clamping techniques.4 In the clampless and selective clamp groups, there was less deterioration of postoperative renal function during the first three months. However, this benefit was not evident six months postoperatively, if warm ischemia was between 20-30 minutes.

Next, Dr. Canda discussed the topic of T1 tumors. The first paper, published in 2017 in BJUI, compared open to robotic procedures.5 Overall 605 surgeries were analyzed for tetrafecta (rate of positive surgical margins, complications, >80% renal function preservation and no chronic kidney disease upstaging). The overall tetrafecta rate was 38%, with a similar tetrafecta rate between both modalities for T1a tumors. However, for T1b tumors, the RAPN had a higher tetrafecta rate (43% vs. 21.3%, p<0.01). RAPN appears to be a safe, minimally invasive surgical modality, with excellent surgical and oncological outcomes in T1 tumors.

Dr. Canda moved on to discuss papers dealing with T2 tumors. A paper published in 2018 in European Urology Journal assessed 298 patients undergoing RAPN for T2 tumors.6 The median tumor size was 7.6 cm, with a median ischemia time of 25 minutes and median estimated blood loss of 150 cc. Only 5.4% of patients had experienced a complication, and lower RENAL nephrometry score and a lower tumor size were protective against postoperative complications in multivariable analyses. The positive surgical margins rate was 8%, and at a median follow-up of 12 months, there were ten deaths and 25 recurrences/metastasis events. Dr. Canda concluded that RAPN could be safely performed with acceptable outcomes in selected clinical stage T2 tumors.

The topic of cystic tumors was next discussed. A paper published in BJUI in 2016 described the Vattikuti experience in RAPN for the management of renal cystic tumors.7 A total of 465 RAPN cases were described, with 12% (54 cases) being cystic tumors. The results demonstrated that these tumors were associated with a significantly lower operative time, although blood loss, warm ischemia time, positive surgical margin rate, and postoperative renal function were similar. Multivariable analysis demonstrated that cystic tumors were not associated with a significantly lower risk of any grade postoperative complication. Again, RAPN proved to be a safe and effective procedure in the surgical management of cystic renal tumors.

Complex tumors were next discussed. A paper published in 2016 in the international journal of urology described the utilization of RAPN for complex cystic renal tumors.8 In this paper, a comparison was performed between 263 RAPNs for solid tumors and 32 RAPNs of complex cystic tumors. No significant differences were noted in the warm ischemia time, estimated blood loss, trifecta achievement, length of hospital stay, complication rate, and renal function preservation. The 5-year cancer free survival, cancer-specific survival, and overall survival were also similar. Another paper compared open PN to RAPN, demonstrating that RAPN had less estimated blood loss, shorter length of hospital stay, and a lower rate of postoperative complications.9 RAPN was demonstrated again to be a safe and effective treatment for complex renal tumors that were previously reserved for open PN in the pure laparoscopic era.

Endophytic tumors were the next topic presented. In a paper published in 2018 in the Journal of Surgical Oncology RAPN was compared to open PN in entirely endophytic tumors.10 A total of 64 RAPN patients were compared to 76 open PN patients. RAPN was demonstrated to have longer operating times (169 min vs. 140 min, p=0.03), shorter warm ischemia time (13 vs. 18 minutes, p=0.001), and a comparable trifecta and complication rate between both modalities. Dr. Canda concluded that for entirely endophytic tumors, both RAPN and open PN offer good trifecta achievement. This encourages the use of RAPN even for these complex tumors if this is the surgeon’s preferred surgical approach. RAPN is a safe and effective alternative to open PN with the advantages of a shorter length of stay and less blood loss.

Lastly, the topic of training was mentioned by Dr. Canda. He described the elaborate ERUS structured training curriculum for RAPN (see another Urotoday summary from this meeting on ERUS training curriculum),11 that enables the training of novice robotic surgeons in RAPN. This program has been validated and has been used to train surgeons from the beginning stage to the level of performing a RAPN independently in a safe and effective manner.

Presented by: A. Erdem Canda, Koc University, Istanbul, Turkey

Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre, Twitter:@GoldbergHanan at the EAU Robotic Urology Section (ERUS) Meeting - September 5 - 7, 2018 - Marseille, France

References:

1.Thompson RH, Lane BR, Lohse CM, et al. Every minute counts when the renal hilum is clamped during partial nephrectomy. European urology 2010; 58(3): 340-5.
2.Porpiglia F, Bertolo R, Amparore D, et al. Evaluation of functional outcomes after laparoscopic partial nephrectomy using renal scintigraphy: clamped vs clampless technique. BJU international 2015; 115(4): 606-12.
3.Liu W, Li Y, Chen M, et al. Off-clamp versus complete hilar control partial nephrectomy for renal cell carcinoma: a systematic review and meta-analysis. Journal of endourology 2014; 28(5): 567-76.
4.Komninos C, Shin TY, Tuliao P, et al. Renal function is the same 6 months after robot-assisted partial nephrectomy regardless of clamp technique: analysis of outcomes for off-clamp, selective arterial clamp and main artery clamp techniques, with a minimum follow-up of 1 year. BJU international 2015; 115(6): 921-8.
5.Maurice MJ, Ramirez D, Kara O, et al. Optimum outcome achievement in partial nephrectomy for T1 renal masses: a contemporary analysis of open and robot-assisted cases. BJU international 2017; 120(4): 537-43.
6.Bertolo R, Autorino R, Simone G, et al. Outcomes of Robot-assisted Partial Nephrectomy for Clinical T2 Renal Tumors: A Multicenter Analysis (ROSULA Collaborative Group). European urology 2018; 74(2): 226-32.
7.Novara G, La Falce S, Abaza R, et al. Robot-assisted partial nephrectomy in cystic tumours: analysis of the Vattikuti Global Quality Initiative in Robotic Urologic Surgery (GQI-RUS) database. BJU international 2016; 117(4): 642-7.
8.Abdel Raheem A, Alatawi A, Soto I, et al. Robot-assisted partial nephrectomy confers excellent long-term outcomes for the treatment of complex cystic renal tumors: Median follow up of 58 months. International journal of urology : official journal of the Japanese Urological Association 2016; 23(12): 976-82.
9.Wang Y, Shao J, Ma X, et al. Robotic and open partial nephrectomy for complex renal tumors: a matched-pair comparison with a long-term follow-up. World journal of urology 2017; 35(1): 73-80.
10.Harke NN, Mandel P, Witt JH, et al. Are there limits of robotic partial nephrectomy? TRIFECTA outcomes of open and robotic partial nephrectomy for completely endophytic renal tumors. 2018.
11. Larcher A. et al. J Urol Suppl 2018
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