826P - Contribution of Tumor Burden and Body Composition Parameters As Prognostic Factors of Metastatic Renal Cell Carcinoma (Mrcc) Treated By Targeted Therapy

Abstract

ABSTRACT Aim: We previously showed that tumor burden (TB) and skeletal muscle density (SMD) at baseline are independent prognostic factors for overall survival (OS) in mRCC. We aimed to analyze the respective roles of baseline TB and Heng score, baseline and 12 week- body mass index (BMI) (weight /height2) and body composition (BC) on OS in mRCC included in trials evaluating targeted therapy. Methods: Baseline and 12 weeks- TB, BMI, adipose tissue (AT), muscular muscle (MM) and SMD were assessed using previously reported techniques. To withdraw causes of early death, OS was estimated from 12 weeks after therapy initiation, using Kaplan-Meier method and compared across strata using log-rank test. To identify prognostic factors, impact of baseline and 12 week- body components were assessed in a multivariable Cox proportional hazards models adjusted for Heng risk groups. Results: 116 pts, treated with sorafenib (n = 35), sunitinib (n = 33) or everolimus (n = 18) or placebo (n = 30) with full data for TB, BMI and BC, have been analyzed. BMI was low ( 25 kg2/m2) in 3 (3%), 47 (41%) and 66 (56%) pts respectively. Median OS was 18 months, 95% Confidence Interval (CI) = [16;21]. Median estimates and hazard ratios derivated from the multivariable Cox model were: Median OS (weeks) Hazard Ratio (95%CI) p-value Heng risk High 6 1 - 0.0002 Intermediate 45 0.2 0.1 – 0.6 Favorable 112 0.1 0.0 – 0.3 TB >= 19 cm 76 1 - 0.0002 9.5-19 cm 85 1.2 0.7 – 2.1 161 0.4 0.2 – 0.7 BMI Normal 112 1 - 0.007 Low 154 0.8 0.2-3.2 High 66 1.9 1.2 – 3.1 SMD and BC were not independently associated with OS. Conclusions: High/intermediate risk Heng score, large TB and high BMI are independent predictors of shorter survival in pts alive after 12 weeks of treatment. Mechanisms underlying the surprising deleterious effect of high BMI could not be determined from body composition impact analysis. After adjustment on TB, high muscle density is not protective any more. Disclosure: Y. Loriot: Advisory board Bayer; B. Escudier: Advisory board Bayer, Pfizer, Novartis Honoraria from Bayer, Roche, Pfizer, Genentech, Novartis, AVEO, GSK. All other authors have declared no conflicts of interest.