ABSTRACT
Symptom clusters are a way of categorically organizing symptoms that occur together as a result of a specific disease and/or as a result of the treatment of that disease. Advanced cancer patients often present with multiple concurrent symptoms that may have a synergistic effect on patient morbidity. Previous research in oncology has suggested that certain symptoms tend to occur together, stay relatively stable over time and remain independent of other symptoms, with or without a shared etiology. In order to better appreciate the symptomatology of advanced cancer, it is important to understand how symptoms develop and interact with one another so that they can be more appropriately managed.
Including quality of life and symptoms as a component of palliative treatment assessment is emphasized in studies of symptom clusters in brain and bone metastases patients undergoing radiation therapy (RT). Radiation-induced nausea and vomiting may be very distressing for a large proportion of palliative patients undergoing RT. The dynamic nature of symptom clusters was shown in several studies, where some symptoms such as fatigue and drowsiness consistently clustered together, while other symptoms such as nausea and loss of appetite shifted into different clusters at each follow-up interval.
Investigation of symptom clusters is complicated and is influenced by several conceptual, methodological and patient-related factors. Further research to explore the mechanisms underlying symptom clusters and the stability of clusters over time will validate research on this concept.
