Impact of Body Mass Index on the Prognosis of Patients Undergoing Radical Nephrectomy for Non-metastatic Renal Cell Carcinoma

Abstract

Purpose:This study was performed to investigate the association between body mass index(BMI) and prognosis in patients undergoing radical nephrectomy for non-metastatic renal cell carcinoma(RCC). Material and Methods :We reviewed the records of 129 patients who underwent radical nephrectomy for non-metastatic RCC at our institution and whose BMI data were available for analysis. Patients were grouped according to BMI based on the Asia-Pacific criteria for obesity as normal (18.5-22.9kg/m2), overweight(23-24.9kg/m2), and obese(≥25kg/m2). Demographic and clinicopathologic parameters were analyzed. Results:On the basis of BMI, 54 patients(41.9%) were categorized as normal, 37(28.7%) as overweight, and 38(29.4%) as obese. The three groups were not significantly different with respect to age, smoking history, presenting symptoms, tumor histology, tumor size, T stage, or grade, except sex. The cancer-specific and disease-free survival rates at 5 years were 89.9% and 87.7%, respectively, for normal patients, 76.3% and 76.3%, respectively, for overweight patients, and 94.1% and 90.8%, respectively, for obese patients, with no significant differences noted among the groups. Univariate analysis identified presenting symptoms, tumor size, T stage, and grade as significant prognostic factors for cancer-specific survival, whereas multivariate analysis indicated that presenting symptoms, tumor size, and T stage were independent prognostic factors. BMI was not a significant prognostic factor for cancer-specific survival.