Abstract
BACKGROUND: Comparing subgroups with different patterns of change in symptom intensity would assist in sorting out individuals at risk for more severe symptoms and worse functional outcomes. OBJECTIVES: The objectives of this study were to identify and compare subgroups of breast cancer patients with different patterns of change in a psychoneurological symptom cluster intensity across the treatment trajectory. METHODS: This secondary analysis used the data from 160 breast cancer patients undergoing chemotherapy or radiation treatment. Psychoneurological symptom cluster intensity was a composite score of 5 symptoms (depressed mood, cognitive disturbance, fatigue, insomnia, and pain) in a psychoneurological cluster at each of 3 time points (ie, at baseline and at 2 follow-ups after chemotherapy or radiation treatment). RESULTS: Five distinct subgroups representing different patterns of psychoneurological symptom cluster intensity during breast cancer treatment were identified: the gradually increasing pattern subgroup (group 1), the constantly low pattern subgroup (group 2), the start low with dramatic increase and decrease pattern subgroup (group 3), the constantly high pattern subgroup (group 4), and the start high with dramatic decrease and leveling pattern subgroup (group 5). Patients without previous cancer treatment experience, with higher level of education, treated with chemotherapy, and/or with more limitations at the baseline were more likely to follow the pattern group 4. Patients in group 4 had the most serious functional limitations measured at the second follow-up time point. CONCLUSION: The results suggest the need to evaluate interventions for specific subgroups and to examine the causal mechanisms underlying a psychoneurological symptom cluster. IMPLICATION: Clinicians should consider these diverse symptom experiences for assessment/management.