AUA 2018: Crossfire: Controversies in Urology: Kidney Cancer

San Francisco, CA USA ( Ralph V. Clayman, MD opened the debate by proposing the use of thermal ablation in the case of a 62 year-old healthy man with a 3 cm posterolateral renal mass. This is of relevance as the rising use of computed tomography has lead to the increased discovery of renal masses of 3 cm of less.

First up in the debate was Dr. Jaime Landman, who argued for the “Pro” side of thermal ablation. Dr. Landman began by showing data on the sensitivity, specificity, and complication rates for renal, breast, lung, pancreas, thyroid, liver, and prostate biopsies. He argued that renal biopsies have a more favorable sensitivity, specificity, and complications profile than most other biopsies. Furthermore, Dr. Landman emphasized how 70% of renal masses biopsies reveal benign disease, not requiring surgical intervention.

When renal masses do require intervention, percutaneous cryoablation has been shown to not have any significant difference in cancer-specific survival (Pierorazio et al., 2016) and metastasis-free survival (Thompson et al., 2015), when compared to partial nephrectomy (PN). Unfortunately, cryoablation does have a lower recurrence-free survival when compared to PN (89% vs. 99%, respectively). However, Dr. Landman argued that salvage percutaneous cryoablation has an 85% success rate (Okhunov et al., 2016). In addition, cryoablation offers significantly better preservation of renal function when compared to PN (Woldu et al. 2015). Finally, percutaneous cryoablation is a more minimally invasive approach with less morbidity when compared to PN (Pierorazio et al., 2016).

Next up was Dr. Ketan Badani who argued for the “Con” side of ablation. He proposed that incomplete ablations and repeat procedures are a serious problem, especially since percutaneous cryoablation is associated with a significantly increased risk of incomplete ablation and decreased cancer-specific survival, when compared to laparoscopic cryoablation (Aboumarzouk et al., 2018). He went back and highlighted the 15% failure rate of repeat percutaneous cryoablation (Okhunov et al., 2016) and showed that salvage PN for these failures are associated with increased patient morbidity (Jimenez et al., 2016; Karam et al., 2015). Dr. Badani showed a study by Thompson et al. (2015), which found that PN had better metastasis-free survival when compared to percutaneous cryoablation. He also pointed out that, although recurrence-free survival appeared similar between PN and cryoablation, the study was in fact flawed as there was no matching for tumor complexity and significantly more malignant histology in the PN cohort. Finally, he concluded that the complications rate between percutaneous cryoablation and partial nephrectomy are similar, despite ablation being more minimally invasive (Moskowitz et al., 2017).

Dr. R. Houston Thompson provided the rebuttal for the “Pro” side of ablation. Dr. Thompson argued that percutaneous ablation is a viable alternative, per the AUA guidelines, in certain situations. Citing his own work (Thompson et al., 2015), he showed that there were no significant differences in cancer-specific, recurrence-free, or metastasis-free survival between patients who received radiofrequency ablation, cryoablation, and PN. He did concede that percutaneous cryoablation is not perfect and complications (e.g., tumor recurrence, perinephric hematoma, and urine leak) can occur. However, percutaneous cryoablation has applications in those patients with perioperative morbidity, including those with prior abdominal surgery or with difficult-to-manage perinephric fat.

Dr. Craig Rogers presented the rebuttal for the “Con” side of ablation. Dr. Rogers argued that the “planets and stars have to align” for thermal ablation to be used. In other words, thermal ablation should only be used in those patients with a tumor not too large; not too endophytic; not too cystic; not anterior or medial near bowel; not hilar; not abutting the ureter; not upper pole abutting the lung, pancreas, or spleen; and the patient has to neither be a candidate for partial nephrectomy nor be interested in active surveillance. Finally, he argued that the 62 year-old patient in question is too young with a life expectancy of greater than 15 years, and there is not enough evidence for the use of thermal ablation in these types of patients.

A final audience poll conducted by Dr. Clayman showed that 90% would not treat the patient in question with thermal ablation. A second question asked the audience what they would do with their “own” 3 cm exophytic renal mass. Partial nephrectomy received 60% of the responses and renal mass biopsy received 35% of the responses.

Pro - Jaime Landman, M.D., University of California Irvine
Con - Ketan Badani, M.D., Icahn School of Medicine at Mount Sinai Hospital
Pro - R. Houston Thompson, M.D., Mayo Clinic
Con - Craig Rogers, MD, FACS, Vattikuti Urology Institute

Written by: Michael Owyong, Department of Urology, University of California-Irvine at the 2018 AUA Annual Meeting - May 18 - 21, 2018 – San Francisco, CA USA