Tumour diameter and decreased preoperative estimated glomerular filtration rate are independently correlated in patients with renal cell carcinoma

Study Type – Diagnosis (exploratory cohort) Level of Evidence 2b What’s known on the subject? and What does the study add? For over 30 years it has been recognized that there is an association between end-stage renal disease (ESRD) and the development of malignancy, particularly renal cortical tumour. Observational studies have consistently shown that patients with severely decreased glomerular filtration rate (GFR) develop cancer more frequently than their age- and exposure-matched controls. This study is the first of its kind to look directly at the relationship between GFR and tumour size, in an effort to begin to examine the relationship between kidney function and oncogenesis. OBJECTIVE • To examine the relationship between tumour diameter and estimated GFR (eGFR) in patients with renal cell carcinoma (RCC). PATIENTS AND METHODS • In total, 1009 patients undergoing partial or radical nephrectomy for unilateral RCC were identified in the Columbia Urologic Database. • eGFR was calculated using the modification of diet in renal disease equation using demographic data and preoperative serum creatinine values. • Data on patient demographics, tumour characteristics, and comorbidities were analyzed using univariate and multivariate regression analysis. RESULTS • Mean (sd, range) tumour diameter was 5.29 (3.8, 0.3–29) cm. Mean (sd, range) eGFR was 75 (23.4, 3–173) mL/min per 1.73 m2. • In multivariate regression analysis, tumour diameter independently predicted decreased preoperative eGFR (coefficient, −0.513; P= 0.008) when controlling for hypertension and race. • Consistent with this, decreased preoperative eGFR independently predicted increased tumour diameter (coefficient, −0.013; P= 0.007) when controlling for race, histology and smoking status. CONCLUSION • Tumour diameter and decreased preoperative eGFR are independently correlated in patients with RCC.