Study on the Influence of Sunitinib and Sorafenib on Fatigue, QoL, Depression in Patients With Metastatic RCC or GIST

The purpose of this study is to assess the influence of Sunitinib and Sorafenib on fatigue, quality of life and depression in patients with metastatic renal cell or colorectal cancer or GIST. In order to get more insight in the mechanism of vascular endothelial growth factor (VEGF) related fatigue and if possible to come to a resolution for this side effect.