Impact of Tumor Size on Renal Function and Prediction of Renal Insufficiency After Radical Nephrectomy in Patients With Renal Cell Carcinoma

Purpose: From the perspective of oncological and functional outcomes partial nephrectomy is considered standard surgery for small renal tumors 4 cm or less. However, radical nephrectomy is commonly done for small tumors. It is important to predict postoperative renal function in patients to choose the most optimal surgical procedure. Materials and Methods: We retrospectively reviewed the records of 271 patients treated with radical nephrectomy for renal cell carcinoma. Associations of tumor size and clinical variables with renal function were analyzed. Results: Preoperatively the mean +/- SD glomerular filtration rate was 74.38 +/- 17.70 ml per minute/1.73 m(2) and 56 patients (20%) had renal insufficiency (glomerular filtration rate less than 60 ml per minute/1.73 m(2)). The mean decrease in the glomerular filtration rate after radical nephrectomy was 24.2 +/- 12.40 ml per minute/1.73 m(2) (31.5% +/- 15%). Of 215 patients with a preoperative glomerular filtration rate of 60 ml per minute/1.73 m(2) or greater 165 (77%) had new onset renal insufficiency. Age, tumor size, preoperative glomerular filtration rate and hypertension were significantly associated with new onset renal insufficiency. Multivariate analysis revealed that age 60 years or greater, tumor size 7 cm or less and the preoperative glomerular filtration rate were independent risk factors for new onset renal insufficiency (p < 0.05). Finally, we developed a predictive model for new onset renal insufficiency after radical nephrectomy. Conclusions: Tumor size 7 cm or less, age 60 years or greater and a decreased preoperative glomerular filtration rate were significant risk factors for new onset renal insufficiency in patients treated with radical nephrectomy. Partial nephrectomy might be considered an option according to the risk of postoperative renal insufficiency, especially in elderly patients with a tumor of 7 cm or less.