This session pit four experts, two supporting each side, against each other to answer this question as it pertains specifically to T1b and T2 renal carcinoma.
Dr. Ketan Bedani opened the debate for the “Pro” side in favor of radical nephrectomy with a review of several familiar arguments for his side. He emphasized the widely-acknowledged lower rate of perioperative complications associated with radical nephrectomy, the (largely theoretical) risk of inferior oncologic outcomes, and the dangers of using retrospective data to guide treatment decisions when allocation to treatment groups is so likely to be driven by unmeasured confounding. Adding to these, he called into question the primary claimed advantage of partial nephrectomy - that it preserves renal function - by citing data from EORTC 30904 showing no difference in rates of advanced kidney disease, as well as his own institution’s database which showed no difference in EGFR in the medium to long term. (The Mount Sinai Multicenter Collaborative Database will be presented here at AUA2019 as MP 42-20 A Comparison of Long-Term Outcomes Between Partial Nephrectomy and Radical Nephrectomy for Clinical Stage T1b and T2 Renal Tumors.) Finally, he again cited his own institutional data, this time showing relatively high rates (~30%) of upstaging of T1b and T2 tumors to T3a upon radical nephrectomy.
Dr. Christopher Porter took up the mantel for partial nephrectomy, beginning by citing the aforementioned retrospective data showing similar survival and oncologic outcomes in patients undergoing radical and partial nephrectomy with superior postoperative glomerular filtration rate (GFR) by approximately 12.4ml/min in the partial nephrectomy group. He highlighted the clinical importance of this difference by showing increased rates of end-stage renal disease in live kidney donors as well as the association between decreased GFR and shorter overall survival. Finally, he showed data from EORTC confirming that while there was no difference in the rates of advanced kidney disease as measured with a threshold of GFR <30, radical nephrectomy did result in a decrease in GFR measured as a continuous variable of ~10ml/min.
Dr. Lindsey Herrel countered the relevance of these differences in GFR, citing a different cohort of kidney donors where no difference in overall survival was noted relative to matched controls to the general population. She used this to emphasize the difference between surgically and medically-induced decline in GFR, with the latter being the driver of the poorer outcomes cited by Dr. Porter and with radical nephrectomy being unlikely to have a clinically meaningful impact on patients with normal renal function preoperatively. She went on to support Dr. Bedani’s concern regarding the risk of upstaging in larger and more complex tumors, citing several other institutional databases showing that >50% of tumors larger than 4-5 cm will be upgraded to T3 after resection and well over 80% of them will be found to be Fuhrman grade 3 or 4, which may suggest a benefit of wider resection in these patients.
Finally, Dr. R Houston Thompson concluded with a tour of several of the retrospective studies associating partial nephrectomy with superior outcomes. He addressed the issue of selection bias, saying that the differences in survival seen in these studies “shows that we are selecting patients well” for partial nephrectomy.
Ultimately, it is unlikely that there will ever be agreement for all cases of T1b and T2 tumors, but the common theme amongst all speakers was the importance of patient selection, with pre-existing renal disease (in addition to the absolute indications of solitary kidney, bilateral tumor, etc) strongly favoring partial nephrectomy and increased tumor size or complexity favoring radical surgery.
Moderated by: Matthew Gettman, MD. Mayo Clinic, Rochester MN
(Pro) Ketan Badani, MD Vice Chair of Urology and Director of Robotic Operations Icahn School of Medicine at Mount Sinai Hospital, New York NY; Lindsey Herrel, MD. University of Michigan
(Con) R. Houston Thompson, MD. Mayo Clinic, Rochester MN; Christopher Porter, MD. Virginia Mason Medical Center/Univ Washington. Seattle, WA
Written by: Marshall Strother, MD, Chief Resident, Division of Urology, University of Pennsylvania, Philadelphia PA at the American Urological Association's 2019 Annual Meeting (AUA 2019), May 3 – 6, 2019 in Chicago, Illinois