Body Mass Index and Survival in a Prospective Randomized Trial of Localized High-Risk Renal Cell Carcinoma

The relationship between adiposity and renal cell carcinoma is poorly understood. Prior studies have suggested body mass index (BMI) may be associated with indolent disease.

We reviewed the clinicopathologic records of 845 patients across 14 countries who were enrolled in a prospective, placebo-controlled study of adjuvant girentuximab treatment for high-risk renal cell carcinoma. Clinical features analyzed included age, gender, race, BMI, and performance status. BMI was stratified into <25 kg/m(2), 25.0-29.9 kg/m(2), 30.0-34.9 kg/m(2), and ≥35 kg/m(2) We examined the association of BMI with stage and survival using logistic and Cox regression analyses, respectively.

845 patients were included for analysis. The majority (72%) were overweight/obese. There was an inverse relationship between BMI and lymph node involvement (P = 0.04). Obesity was associated with improved disease-free and overall survival (log rank <0.01 for both). When compared with normal weight subjects, those with a BMI 30-34.9 [HR 0.50; 95% confidence interval (CI) 0.31-0.81] and BMI ≥35 (HR 0.24; 95% CI 0.09-0.60) had significantly improved overall survival. A trend towards improved disease-free survival was found among subjects with BMI 30-34.9 (HR 0.77; 95% CI 0.56-1.05) and ≥35 (HR 0.74; 95% CI, 0.48-1.15).

In a prospective cohort of nephrectomized patients with high-risk disease, obesity is associated with lower risk of lymphatic spread and improved overall survival.

This is the first study utilizing data from a prospective randomized trial reporting an association between obesity and improved overall survival for patients with clear cell renal cell carcinoma. Cancer Epidemiol Biomarkers Prev; 25(9); 1326-32. ©2016 AACR.