Potentially curative therapy (surgery, chemotherapy, radiotherapy) is always the first line of treatment for cancer patients. Cancer pain therapy is symptomatic therapy with the goal of effective reduction of pain (pain at rest VAS <3, pain at movement VAS <6) and preservation of a good quality of life (minimizing side effects of the pain therapy). Cancer pain can be influenced negatively by psychological disorders and dysfunctional behavior. If cancer pain is not treated sufficiently, impairment of various aspects of quality of life affecting the progress of the disease and functional status of the patient are likely to occur. Quality of life can also be reduced by inappropriate invasive pain therapy or inappropriate pharmacological therapy causing disabling side-effects.