Chronic Kidney Disease and Kidney Cancer Surgery: New Perspectives

We sought to provide a contemporary understanding of chronic kidney disease and its relevance to kidney cancer surgery. Another purpose was to resolve points of discrepancy regarding the survival benefits of partial vs radical nephrectomy by critically evaluating the results of prospective and retrospective studies in the urological literature.

We performed a comprehensive literature search for relevant articles listed in MEDLINE® from 2002 to 2018 using the key words radical nephrectomy, partial nephrectomy, glomerular filtration rate, kidney function and chronic kidney disease. We also assessed select review articles and society guidelines about chronic kidney disease pertinent to urology and nephrology.

Complete evaluation of the potential consequences of chronic kidney disease involves assessment of the cause, the glomerular filtration rate level and the degree of albuminuria. Chronic kidney disease is commonly defined in the urological literature solely as a glomerular filtration rate less than 60 ml/minute/1.73 m². This ignores the significance of the cause of chronic kidney disease, and the presence and degree of albuminuria. Although this glomerular filtration rate is relevant for preoperative assessment of patients who undergo surgery of kidney tumors, recent studies suggest that a glomerular filtration rate less than 45 ml/minute/1.73 m² represents a more discerning postoperative prognostic threshold. Reported survival benefits of partial over radical nephrectomy in retrospective studies were likely influenced by selection bias. The lack of survival benefit in the partial nephrectomy cohort in the only randomized trial of partial vs radical nephrectomy was consistent with data demonstrating that patients in each study arm were at relatively low risk for mortality due to chronic kidney disease when accounting for the chronic kidney disease etiology and the postoperative glomerular filtration rate.

The prognostic risk of chronic kidney disease in patients with kidney cancer is increased when the preoperative glomerular filtration rate is less than 60 ml/minute/1.73 m² or the postoperative rate is less than 45 ml/minute/1.73 m². Additional factors, including nonsurgical causes of chronic kidney disease and the degree of albuminuria, can also dramatically alter the consequences of chronic kidney disease after kidney cancer surgery. Urologists must have a comprehensive knowledge of chronic kidney disease to assess the risks and benefits of partial vs radical nephrectomy when managing tumors with increased complexity and/or oncologic aggressiveness.