Roles of biological and psychosocial factors in experiencing a psychoneurological symptom cluster in cancer patients

Purpose: (a) To identify subgroups with unique psychoneurological symptom-cluster experience (depression, cognitive impairment, fatigue, sleep disturbance, and pain) and (b) to examine whether the selected demographic, clinical, psychological, and biological factors determine a symptom-cluster experience in cancer patients. Method: The sample included 203 patients with diverse cancer types recruited from a Korean university hospital. Latent profile analyses were conducted to identify subgroups. Influencing factors of subgroup membership (demographic/clinical variables, hemoglobin level, social support, and psychological stress) were included as covariates in latent profile analysis and analyzed by multinomial logistic regression. Results: Latent profile analyses classified patients into two subgroups with a unique symptom cluster experience: patients experiencing high intensity in all symptoms within the cluster (the all-high-symptom subgroup, 71%) and patients experiencing low intensity in all symptoms within the cluster (all-low-symptom subgroup, 29%). The validity of the two subgroups was confirmed by the group classification accuracy (97% of the all-low-symptom subgroup and 99% of the all-high-symptom subgroup) and by significant Wald's mean equality tests, showing each symptom (depression, cognitive impairment, fatigue, sleep disturbance, and pain) significantly differentiated the two subgroups (ps <.001). Psychological stress independently determined the subgroup membership. Patients with high levels of stress were more likely to be in the all-high-symptom group (OR = 4.69, p <.0001). Hemoglobin level, cancer diagnosis, social support, and previous chemotherapy experience did not influence group membership. Conclusions: A large number of patients experience five psychoneurological symptoms simultaneously due to psychological stress. Interventions targeted to stress would be beneficial for those patients.