Quality of life is an individual perception of life, values, objectives, standards, and interests in the framework of culture. A number of illness-related factors exist that can affect quality of life. The term quality of life is increasingly being used as a primary outcome measure in studies to evaluate the effectiveness of treatment. Patients, generally, instead of measuring lipoprotein level, blood pressure, and the electrocardiogram, make decisions about their health care by means of quality of life which estimates the effects on outcomes important to themselves.
An increasingly important issue in oncology is to evaluate the quality of life in cancer patients. The cancer-specific quality of life is related to all stages of this disease. In fact, for all types of cancer patients, general instruments can be used to assess the overall impact of the patient's health status, based on their quality of life; however, on the other hand, cancer-specific instruments assess the impact of a specific cancer on quality of life. In some forms of cancer (Giloma for instance), quality of life has become an important endpoint for treatment comparison, in randomized controlled trials, so that in these patients clinical studies increasingly incorporate quality of life as an endpoint.