Prognostic significance of sarcopenia and decreased relative dose intensity during the initial two cycles of first-line sunitinib for metastatic renal cell carcinoma.

Targeted therapy for metastatic renal cell carcinoma (mRCC) treatment requires the identification of clinically important factors that can predict the therapeutic effect. We retrospectively investigated the prognostic roles of pre-treatment sarcopenia and relative dose intensity during the initial two cycles (2c-RDI) of sunitinib treatment in patients with mRCC. In total, 41 (52.6%) patients were classified as having sarcopenia and 16 (20.5%) patients were classified with low 2c-RDI at <75%. The mean dose reduction during sunitinib treatment was higher for sarcopenic than for non-sarcopenic patients. The median progression-free survival (PFS) and overall survival (OS) were significantly shorter in sarcopenic patients with low 2c-RDI (n = 14, 17.9%) than in non-sarcopenic patients with high 2c-RDI (n = 35, 44.9%). Multivariate analysis identified sarcopenia and low 2c-RDI as poor prognostic factors for PFS and OS. Our findings provide new insights into the prognostic role of sarcopenia and 2c-RDI for targeted therapy in mRCC.