Iscador Qu as Supportive Treatment in Colorectal Cancer (Union International Cancer Control, UICC Stages II-IV)
Efficacy and safety of a supportive treatment with European mistletoe extract Iscador® Qu ("quercus", i.e. from oak tree) in patients with colorectal cancer (Union for International Cancer Control, UICC stages II-IV), in addition to post-operative conventional oncological therapy (radio-, chemo-, targeted therapy) as compared to a parallel group with conventional therapy only. Primary Endpoints: Reduction of adverse effects of conventional therapy; reduction of therapy or disease induced symptoms (both are quality of life parameters and evaluated after 1 year); prolongation of disease free and/or overall survival (DFS, OS) after 5 years. Prospective observational confirmation study of previous retrospective cohort study. As this is a non-interventional cohort study, all therapies and measurements are performed on directive by the treating physician and/or request by the patient only.