Purpose : This study aimed to analyze the impact of patients’ nutritional status and changes in body composition on the prognosis of metastatic renal cell carcinoma (mRCC) patients who received systemic therapy with tyrosine kinase inhibitors (TKIs). Methods : A total of 57 mRCC patients who received systemic therapy with TKIs as first-line therapy at our facility between November 2004 and October 2018 were included. The Prognostic Nutritional Index (PNI) was used to evaluate their nutritional status. The volumes of skeletal muscle mass and fat tissue were calculated using the SYNAPSE VINCENT system. The effects of nutritional status and body composition of mRCC patients on progression-free survival (PFS) and overall survival (OS) were analyzed using Cox regression methods. Results : Low PNI at the start of systemic therapy was a significant prognostic predictor for OS (HR 3.807 [95% CI 1.205-12.027], P = 0.046), and it was related to loss of muscle mass three months after systemic therapy. Although the loss of muscle mass at the start of systemic therapy was not associated with OS, loss of muscle mass during treatment predicted worse OS. Conclusions : Nutritional status of mRCC patients may predict changes in body composition and be associated with their prognosis
