[Does meditation improve the quality of life for patients living with cancer?].

OBJECTIVE To determine whether interventions that promote meditation improve quality of life in cancer patients. DATA SOURCES MEDLINE data bank (1966 to 2004) using the terms "spiritual well-being" and the MeSH terms "meditation", "neoplasm", "cancer", and "spiritual therapies". STUDY SELECTION Clinical trials evaluating the effect of meditation on cancer patients. SYNTHESIS Five studies were retained; none were designed in a way that made it possible to evaluate the effect of meditation exclusively or its effect on quality of life compared with a neutral intervention. Only 1 evaluated spiritual well-being. Four reported a significant improvement in symptoms of depression and anxiety when the study group's preintervention and post-intervention scores were compared. In the 2 studies that included a control intervention, participants preferred the meditation intervention. CONCLUSION The design of studies to evaluate the effect of meditation on cancer patients did not make it possible to clearly identify the effect of meditation alone. These studies did show, however, that mood and anxiety parameters tend to improve--something that has been documented in other populations--and that spiritual well-being tends to improve as well. The main biases preventing a generalization of the effects of meditation are simultaneous evaluation of several interventions, "diluting" the effect of meditation; the lack of control groups receiving a comparable intervention; and the selection of study populations favourable to the intervention. There is increasing recognition of the effect of improved spiritual well-being on quality of life, even though most tools for measuring quality of life do not have a section for measuring spiritual well-being. Failing to take this aspect into account could be causing us to miss certain effects of meditation. In order to determine whether meditation should be offered to terminally ill patients, we need studies that do not contain these biases--studies designed to measure spiritual well-being.