Inclusion Criteria:  Diagnosed with "Cancer"; Literacy and understanding German language; Signed informed consent;  Exclusion Criteria:  Women who are pregnant or breastfeeding / have the intention to become pregnant during the course of the study; Other clinically significant concomitant disease states (e.g. renal failure, hepatic dysfunction, cardiovascular disease, etc); Known or suspected non-compliance, drug or alcohol abuse; Inability to follow the procedures of the study: e.g. due to language problems, psychological disorders, dementia of the participant, etc; Enrolment of the investigator, his/her family members, employees and other dependent persons; Cognitive impairment: Mini-Mental State Examination (MMSE) < 21; Major Depression or Hospital Anxiety and Depression Scale (HADS) >11 at baseline.