[Therapeutic significance of sunitinib-induced "off-target" side effects].

Sunitinib is a basic medicine in the therapy of metastatic clear cell renal carcinoma. Our aim was to retrospectively evaluate the efficacy of sunitinib in the everyday clinical practice taking the most common side effects and clinical features into consideration. Data of ninety-four patients with metastatic, clear cell renal carcinoma, receiving sunitinib therapy were analyzed retrospectively, regarding efficacy and toxicity. Factors potentially influencing progression-free survival (PFS) and overall survival (OS) [age, nephrectomy, "off-target" side effects that are not connected to vascular endothelial growth factor receptor (VEGFR)] were studied. Complete remission, partial remission and stable disease occurred in 8 (8.5%), 30 (31.9%) and 50 (53.1%) patients, respectively. Objective tumor response developed in 38 (40.4%) cases. Median PFS and OS were 18.3 (95% CI 14.45-22.14) and 27.9 (95% CI 20.95-34.85) months, respectively. PFS and OS were more favorable in case of hypothyreosis (pPFS=0.005, pOS=0.043), hand-foot syndrome (pPFS=0.006, pOS=0.008), grade ≥2 neutropenia (pPFS=0.003, pOS=0.008) and thrombocytopenia (pPFS=0.01, pOS=0.011). Effective therapy of manageable side effects (most of which have potential predictive effect) is important for favorable survival results. Maintenance of dose intensity is also essential in order to compare the daily routine with the efficacy and safety results of clinical trials.