Impact of Symptom Clusters on Quality of Life Outcomes in Patients from Japan with Advanced Nonsmall Cell Lung Cancers

OBJECTIVE: Identify symptom clusters based on symptoms experienced by patients with advanced nonsmall cell lung cancers (NSCLCs), and examine the relationship between the symptom clusters and impairment in everyday life and quality of life (QOL). METHODS: Using the M.D. Anderson Symptom Inventory, 9 symptom items and the QOL Questionnaire (QLQ-C-30) evaluation apparatus from the European Organization for Research and Treatment of Cancer, we evaluated symptom severity, interference in daily life, and QOL. Factor analysis and multiple regression analysis techniques were used. RESULTS: Sixty patients with advanced NSCLCs seen in pulmonary medicine departments were included in the study. The average age of patients was 64.33 (standard deviation = 11.40). Thirty-six were male and 24 were female. Three symptom clusters were identified as fatigue/anorexia cluster (dry mouth, altered the sense of taste, drowsiness, fatigue/tiredness, and lack of appetite), pain cluster (anxiety, sadness, and pain), numbness cluster (numbness, leg weakness, and distress). The pain cluster had the strongest influence (adjusted R(2) = 0.355) on daily life (emotions) while the numbness cluster most strongly affected walking. The fatigue/anorexia cluster explained 22.7% of role function variance. This symptom clustering may be unique among patients with advanced NSCLCs. CONCLUSIONS: Each of these clusters affected QOL and everyday life with varying degrees of influence. In clinical screening assessments, focusing on symptom clusters could provide tailored management strategies for patients with advanced NSCLCs. These care strategies may improve outcomes specifically for advanced NSCLCs patients.