It has already been known for a long time that cancer is a genetic disorder and that the development of the illness is a very complex interaction between genetic and surrounding factors. Also the response on therapy and the development and seriousness of side effects is stipulated by this complicated collaboration of genetic and surrounding factors. Moreover it is not only the DNA that plays an important role but also the systems of control at protein level. At this moment a lot of questions remain to be answered because up till now the studies were of rather restricted statistical strength with frequently inconsistent dates and moreover retrospective. Major retrospective studies are necessary to distinguish the relationship between DNA/protein patterns and clinical relevant endpoints like prognosis and toxicity in which an as broad as possible patient group is being monitored. For this reason we want to draw blood in MAASTRO clinic of all patients with endometrial cancer and store it encrypted so that we can perform DNA and protein analyses in future and to correlate the results with survival and toxicity of the treatment.