LAUSR

BACKGROUND The relationship between weight change during treatment and survival remains poorly characterized in patients with metastatic renal cell carcinoma (mRCC). PATIENTS AND METHODS In this retrospective analysis we included 3311 patients with mRCC treated in phase II/III first-line or second-line targeted therapy clinical trials and assessed the effect of weight change on overall survival (OS), progression-free survival (PFS), and objective response rate (ORR) at 6 and 12 weeks from treatment initiation. Weight change was defined as weight loss (≥5% reduction), weight gain (≥2% increase), or stable weight from baseline. Survival analyses were performed using the Kaplan-Meier method and adjusted for known prognostic factors using Cox regression multivariable analysis. RESULTS Overall, 1916 (58%) had stable weight, 936 (28%) had weight loss, and 459 (14%) had weight gain at 12 weeks. Patients with weight loss at 12 weeks had inferior OS compared with those with stable weight (hazard ratio [HR], 1.494; 95% confidence interval [CI], 1.322-1.688; P < .0001; median OS 18.7 vs. 26.9 months), and shorter PFS (HR, 1.315; 95% CI, 1.189-1.455; P < .0001; median PFS, 7.2 vs. 10.1 months). The ORRs for patients with weight loss, stable weight, and weight gain at 12 weeks were 23.4% (n = 219/936), 32.1% (n = 615/1916), and 35.9% (n = 165/459), respectively (adjusted odds ratio, 0.715; P = .03). Findings were consistent at 6 weeks. Adverse events were similar between groups. CONCLUSION We showed that mRCC patients who experience weight loss during treatment have worse outcomes compared with patients with stable weight at 6 and 12 weeks of treatment. Weight loss at 6 weeks from treatment initiation might be an early clinical biomarker of worse survival and might provide prognostic utility.