Quality of life.

The term quality of life (QL) is a global characterization usually consisting of the following factors: physical function, symptoms from disease and/or treatment, occupational and social interactions, and psychological parameters, including mood with some overall assessment of well-being, such as happiness or satisfaction. For the purposes of individual patient management, the physician often assesses many of these in the process of making decisions about cancer care. The aggregate assessment of QL in groups of patients is more difficult. The increasing subjectivity and difficulty in measurement as medical observers move from the physical (objective parameters) to the psychosocial (subjective parameters) has hindered our ability to study QL. The changing status of the patient from initial symptomatic disease, to the incapacitation related to the treatment and/or the ongoing course of the disease often leading to death makes the measurement of QL a moving target. One must be very specific as to the malignancy, the status of disease, the treatments with their side effects and sequela, and the time of measurement in this dynamic spectrum, if the data is to be comparable and to permit generalizations. For the purposes of clinical trials the emphasis remains with the physical factors: function and symptom control. Even these factors are difficult to assess consistently, making the aggregation of such data from similarly treated groups of patients sometimes suspect. The ability to determine the impact of disease and treatment on these factors in a reliable manner could make possible, with aggregated data from many patients, more objective assessment of the advantages and disadvantages of a particular therapy. Late sequelae of treatment may also be important. When cure or prolonged survival are not likely or possible then the ability to determine the probable effects, physical and psychosocial, of a specific treatment on an individual patient is valuable. Treatment then can be guided to some extent by QL considerations.