Chronic Kidney Disease and Kidney Cancer Surgery: New Perspectives.

To provide a contemporary understanding of chronic kidney disease (CKD) and its relevance to kidney cancer surgery. To resolve points of discrepancy regarding the survival benefits of partial nephrectomy (PN) vs radical nephrectomy (RN) by critically evaluating the results of prospective and retrospective studies in the urologic literature.

A comprehensive literature search for relevant articles listed in MEDLINE® (2002-2018) was performed using keywords radical nephrectomy, partial nephrectomy, glomerular filtration rate (GFR), kidney function, and chronic kidney disease. Selected review articles and society guidelines about CKD pertinent to urology and nephrology were also assessed.

Complete evaluation of the potential consequences of CKD involves assessment of cause, GFR level, and degree of albuminuria. CKD is commonly defined in the urologic literature solely as a GFR <60mL/min/1.73m2, thereby ignoring the significance of CKD cause and the presence/degree of albuminuria. Although this GFR level is relevant for preoperative assessment of patients undergoing surgery for kidney tumors, recent studies suggest that GFR <45mL/min/1.73m2 represents a more discerning postoperative prognostic threshold. Reported survival benefits of PN over RN demonstrated in retrospective studies are likely influenced by selection bias. The lack of survival benefit in the PN cohort of the only randomized trial of PN versus RN is consistent with data demonstrating that patients in both arms of the study had relatively low risk of mortality from CKD, when accounting for etiology of CKD and post-operative GFR levels.

The prognostic risk of CKD for kidney cancer patients is increased whenever the preoperative GFR is <60 ml/min/1.73m2 or the postoperative GFR is <45mL/min/1.73m2. Additional factors including non-surgical causes of CKD and degree of albuminuria can also dramatically alter the consequences of CKD following kidney cancer surgery. Urologists must have a comprehensive knowledge of CKD in order to assess the risks/benefits of PN versus RN when managing tumors with increased complexity and/or oncologic aggressiveness.

The Journal of urology. 2019 May 07 [Epub ahead of print]

William C Huang, Nicholas M Donin, Andrew S Levey, Steven C Campbell

Division of Urologic Oncology, Department of Urology, New York University Langone Medical Center, New York , NY.