ASCO GU 2019: Informing the Decision Using Clinical Trial Evidence - Localized Kidney Cancer
As part of the 2019 Genitourinary Cancers Symposium session on renal cell carcinoma (RCC), Dr. Hendrik Van Poppel from University Hospitals Leuven presented his argument for the utilization of partial nephrectomy in clinically-localized kidney cancer. Beginning in 1981, his group began performing partial nephrectomy in select patients and subsequently presented the data from these 31 patients in 1991. His data suggested that partial nephrectomy is a feasible treatment option in select patients with renal masses. One of the large arguments in favor of performing nephron-sparing surgery (NSS) is that in patients who are at risk for development of medical renal disease, there is maximal preservation of renal parenchyma in order to minimize any surgically-induced decline in renal function. He then showed additional clinical trial data that shows that patients undergoing a partial nephrectomy did tend to have more preservation of renal function (measured by estimated glomerular filtration rate), as compared with patients undergoing radical nephrectomy. This was particularly true for patients who began with an eGFR <45. One of the main goals of preserving maximal renal function is to decrease cardiac-specific survival, as there have been a large number of studies that correlate lower eGFR with an increased risk of cardiac events.
Dr. Van Poppel then reviewed the guidelines on the treatment of RCC, which recommends NSS in patients with low-stage (cT1) RCC whenever possible, and suggests NSS for patients with tumors <7cm, if technically feasible. He next showed a meta-analysis of changes in renal function from Kim et. Al. which pooled all trials that compared NSS to radical nephrectomy. The pooled analysis suggested a 61% risk reduction for severe chronic kidney disease (CKD) and a 19% risk reduction of all-cause mortality. He then reviewed additional studies which suggest that for patients with normal pre-operative eGFR, the actual benefit in the preservation of renal function from NSS may not be significant as compared with radical nephrectomy.
He next stressed the importance of differentiating surgical CKD from medical CKD, as they have differential risks of leading to cardiac-specific and all-cause mortality. He believes it is crucial to identify those patients who are at increased risk of medical CKD, as these patients will continue to have declined in renal function post-operatively if their comorbidities are not aggressively managed. He challenged the urologic dogma that NSS is always better than radical nephrectomy because it lowers the risk of CKD and subsequent cardiac events, by presenting further studies that suggest NSS does not, in fact, decrease the rate of cardiac events. Because most of the studies comparing NSS and radical nephrectomy are retrospective, they are subject to selection bias, which may favor NSS in younger, healthier patients, or those with less aggressive tumor biology.
Van Poppel concluded by stating the need to be judicious when deciding who to perform NSS in. There is likely a clinical benefit to NSS in some patients, particularly in those with pre-existing medical renal disease. He believes that NSS should be offered to these patients, but that not all patients with renal masses that are amenable to partial nephrectomy should be offered NSS. He believes that patients with a T1-T2 renal mass who is elderly, has a Charleston Comorbidity Index (CCI) of >2, has preoperative CKD >2 and/or proteinuria should be more strongly considered for NSS, when technically feasible.
Presented by: Hendrik Van Poppel, MD, PhD, University Hospitals Leuven, Belgium
Written by: Brian Kadow, MD. Society of Urologic Oncology Fellow, Fox Chase Cancer Center at the 2019 American Society of Clinical Oncology Genitourinary Cancers Symposium, (ASCO GU) #GU19, February 14-16, 2019 - San Francisco, CA