Symptom clusters during palliative chemotherapy and their influence on functioning and quality of life

Introduction Symptom management in patients undergoing palliative chemotherapy is challenging, as patients may suffer from cancer symptoms as well as symptoms related to chemotherapy. Symptom clusters are interrelated symptoms occurring simultaneously that exert a negative impact on survival. Identification of symptom clusters and effective symptom management for patients receiving palliative chemotherapy is crucial. Objectives The purpose of this study was to identify symptom clusters among cancer patients undergoing palliative chemotherapy and examine the relationship between symptom clusters and functioning and quality of life (QOL) in these patients. Methods A total of 300 patients undergoing palliative chemotherapy participated in the study. Symptom experience during previous palliative chemotherapy was evaluated using a symptom questionnaire including 20 symptoms. The European Organization for Research and Treatment of Cancer Quality of Life-C30 was used to measure patients' symptoms, functioning and QOL. Factor and hierarchical cluster analyses were performed to identify symptom clusters. Structural equation modeling was used to identify relationships between symptom clusters, functioning and QOL in patients. Results Four symptoms clusters including 14 symptoms were identified of the 20 symptoms experienced by patients undergoing palliative chemotherapy. The emotional cluster had negative influence on role and social functioning. The nausea and vomiting/appetite/taste change cluster had a negative impact on role functioning. The fatigue/cognitive and other cluster (dyspnea, pain, constipation, neuropathy, and sleep disturbance) negatively influenced physical functioning. Among the functioning subscales, only role functioning had a direct influence on QOL. Indirect relationships between symptom clusters and QOL were mediated by physical and role functioning. The final model, which consisted of four symptom clusters and three functioning subscales, accounted for 23.3% of the variance in the QOL. Conclusions Four symptom clusters occurring during palliative chemotherapy demonstrated negative influences on functioning and QOL. Differential contributions of symptom clusters to functioning were identified that eventually contributed to QOL through role functioning. The identified symptom clusters and their relationships with functioning and QOL may help guide approaches to symptom management. Implementation of interventions targeting symptom clusters would contribute to improving functioning and QOL in patients.