Prevalence of baseline chronic kidney disease in patients presenting with solid renal tumors

Objectives: To evaluate the prevalence of baseline chronic kidney disease (CKD) in a large cohort of patients presenting with renal masses to a tertiary care center, omparing serum creatinine (sCr) and estimated glomerular filtration rate (eGFR). sCr inadequately reflects renal function. eGFR and chronic kidney disease CKD stage are more clinically relevant parameters to reflect the risk of morbidity and mortality in patients after nephron loss. Methods: Using the prospectively maintained Fox Chase Kidney Cancer Database, we identified patients undergoing kidney surgery between January 2000 and May 2010. eGFR was calculated using the Modification of Diet in Renal Disease (MDRD) and the CKD-Epidemiology formulas. CKD stages I-V were defined using the National Kidney Foundation definitions. Results: A total of 1114 patients had adequate data available to calculate a preoperative eGFR (mL/min). Although 88% of all patients presenting for surgery at our institution had a "normal" baseline sCr (≤1.4 mg/dL), 22% of patients had CKD stage III or greater. Moreover, of the 282 patients 70 years and older, 40% (113/282) had CKD stage III. Twenty-three percent (51/220) of patients older than 70 years had CKD stage III with a seemingly normal sCr. Conclusions: Many patients with a normal sCr have CKD stage III or higher, particularly patients older than 70 years old. Given the high prevalence of baseline CKD in patients with a solid renal tumor, a concerted effort must be made to preserve renal function when surgically treating solid renal masses.