Psychoneurological symptom cluster trajectories in individuals treated for early-stage breast cancer.

Abstract

The psychoneurological (PN) symptom cluster has been defined in the literature as anxiety, depression, fatigue, sleep disturbance, and pain. PN symptoms are influenced by cancer and its treatment as well as biological and psychosocial factors. The purpose of this analysis was to describe temporal patterns of the PN symptom cluster severity in breast cancer survivors over the year following initial surgical intervention and investigate the time-dependent effect of treatment modality on symptom severity. In a prospective longitudinal study, symptom data were collected from individuals with early-stage breast cancer 48 h after initial surgery and at monthly intervals for the subsequent 12 months using the PROMIS®-29 subscales for anxiety, depression, fatigue, sleep disturbance, and pain. Applying group-based trajectory modeling, we classified participants into subgroups with similar temporal patterns of PN symptom cluster severity and included treatment modality as a time-dependent covariate. Across 353 participants (mean age 60.10 ± 11.9 years, 88.95% white, 66.57% undergoing segmental mastectomies), four distinct trajectory subgroups (mild [47.6%; n = 168], moderate [28.3%; n = 100], severe [15.9%; n = 56], and most severe increasing [8.2%; n = 29]) were revealed for PN symptom cluster severity. Chemotherapy was associated with greater severity in all symptom severity subgroups, while radiation was associated with greater symptom severity in the mild and most severe increasing subgroups. A subgroup of individuals with early-stage breast cancer experienced persistent severe PN symptoms. Future research should focus on psychosocial, biological, and disease-related characteristics of individuals in the most severe symptom group to inform preventative treatments and effective interventions.