Impact of body mass index and weight loss on cancer-specific and overall survival in patients with surgically resected renal cell carcinoma

Objective. This study evaluated the impact of body mass index (BMI) and the influence of preoperative weight loss (WL) in each BMI category on survival in patients with surgically treated renal cell carcinoma (RCC). Material and methods. In total, 834 patients undergoing nephrectomy for RCC were retrospectively reviewed. Overall survival (OS) and cancer-specific survival (CSS) were estimated by Kaplan-Meier analysis. Univariate and multivariate analyses were accomplished to assess the influence of preoperatively assessed clinical parameters, including BMI and WL, on survival. The mean postsurgical follow-up was 85 months (median 79 months, range 12-191 months). Results. Of the patients studied, 251 (30%) presented with a BMI < 25 kg/m(2), while 362 patients (44%) were overweight (BMI >= 25 to < 30 kg/m(2)) and 221 patients (26%) were obese (BMI >= 30 kg/m(2)). Fifty-two patients (6.2%) experienced WL. While BMI did not significantly influence OS and CSS, WL had a significant impact on survival in patients with a BMI < 30 kg/m(2), in contrast to obese patients presenting with a BMI of >= 30 kg/m(2). Further analysis showed overweight to influence significantly disorders in wound healing, but neither other complications nor postoperative mortality. Conclusions. This is the first study providing information regarding the influence of BMI in relation to WL in patients with surgically treated RCC. While BMI did not significantly influence the survival of patients in the present series, WL had a significant impact on survival of patients presenting with a BMI < 30 kg/m(2). Hence, preoperative assessment of WL should be considered for the assessment of individual prognosis.