Does obesity influence the prognosis of metastatic renal cell carcinoma in patients treated with vascular endothelial growth factor-targeted therapy?

BACKGROUND: Obesity increases the risk for renal cell carcinoma (RCC). However, it has only recently been identified as an independent positive prognostic factor for localized RCC.

OBJECTIVE: To determine whether obesity influences long-term prognosis in metastatic RCC patients receiving vascular endothelial growth factor-targeted therapy.

DESIGN, SETTING, AND PARTICIPANTS: In 116 patients with metastatic RCC who received antiangiogenic agents (sunitinib, sorafenib, axitinib, bevacizumab) in 2005-2010, we evaluated whether body mass index (BMI), a body surface area (BSA) above the European average, the visceral fat area (VFA), or s.c. fat area (SFA) were of predictive relevance.

MEASUREMENTS: BMI was categorized based on current World Health Organization definitions. BSA was stratified according to the European average for men (1.98 m(2)) and women (1.74 m(2)). VFA and SFA were dichotomized using the median of the observed distribution as the cutoff. The primary endpoints of this study were time to progression and overall survival time.

RESULTS AND LIMITATIONS: The whole population had median progression-free and overall survival times of 8.3 months and 20.5 months, respectively. In contrast to BMI and BSA, higher than average VFA and SFA levels were significant predictors of longer progression-free and overall survival times. The major limitations of this study are its retrospective design and its heterogeneous patient population.

CONCLUSION: This is the first study to identify high VFA and SFA levels as positive predictive biomarkers for patients who receive first-line antiangiogenic agents for metastatic RCC.