Visceral Obesity in Predicting Oncologic Outcomes of Localized Renal Cell Carcinoma

Purpose: We investigate the clinicopathological features and prognostic significance of visceral obesity in patients with localized renal cell carcinoma. Materials and Methods: This study included 706 patients with localized renal cell carcinoma who had undergone curative surgery between January 2003 and April 2012. Visceral, subcutaneous and total adipose tissue were measured based on preoperative computerized tomography of the umbilical region. Visceral adipose tissue percent was calculated using the formula, VAT% [visceral adipose tissue/total adipose tissue] x 100. The association between clinicopathological factors and visceral obesity was examined. Results: A higher VAT% at diagnosis was associated with older age at diagnosis, higher prevalence of diabetes and higher prevalence of former or current smoking status. The distribution of histological subtypes differed significantly among VAT% quartiles. The proportion of high grade tumors increased as VAT% increased (OR 1.023, 95% CI 1.000-1.126, p = 0.037). A U-shaped association between VAT% quartiles and the risk of disease recurrence was observed for all patients. Disease recurrence was significantly increased in the lowest (HR 3.198, 95% CI 1.765-10.040, p = 0.036) and highest (HR 4.760, 95% CI 2.937-13.210, p = 0.010) VAT% quartiles. Conclusions: Relative visceral obesity as assessed by VAT% was associated with clinicopathological characteristics of localized renal cell carcinoma. A U-shaped association between VAT% quartiles and risk of disease recurrence was observed among patients with localized renal cell carcinoma.