title: Identification of distinct fatigue trajectories in patients with breast cancer undergoing adjuvant chemotherapy.
abstract: OBJECTIVE
  The goal of this study was to characterize changes in daily fatigue in women undergoing chemotherapy for breast cancer. We examined whether there are subgroups of patients with distinct fatigue trajectories and explored potential psychosocial and biomedical predictors of these subgroups.
  
  
  METHODS
  Participants were 77 women with breast cancer receiving adjuvant chemotherapy with AC-T (2-week cycle) and TC or TCH (3-week cycle) regimens. They completed 28 daily ratings online using an adapted version of the Patient-Reported Outcomes Measurement Information System (PROMIS®) fatigue instrument.
  
  
  RESULTS
  Both regimens followed an "inverted-U-shaped" fatigue pattern over approximately 2 weeks. Growth mixture modeling identified three patient subgroups with distinct trajectories. Fatigue scores in the "low fatigue" group (23 %) increased following the infusion and quickly abated. The "transient fatigue" (27 %) group had a very pronounced increase. Patients in the "high fatigue" (50 %) group reported consistently elevated fatigue with a relatively small increase. Demographic and medical variables were not associated with fatigue trajectory. Patients in the "high fatigue" group reported significantly poorer physical, emotional, and social functioning, poorer general health, and more depressed mood than patients in the "low fatigue" group. The "transient fatigue" group reported significantly better physical and social functioning than the "high fatigue" group, but emotional distress and depression similar to the "high fatigue" group.
  
  
  CONCLUSIONS
  The identification of patient subgroups with distinct fatigue trajectories during chemotherapy is an essential step for developing preventative strategies and tailored interventions. Our results suggest that different trajectories are associated with patients' psychosocial and general health.
authors: Dornsife Center for Self-Report Science and Center for Economic and Social Research, University of Southern California, Verna & Peter Dauterive Hall, 635 Downey Way, Los Angeles, CA, 90089-3332, USA, junghaen@usc.edu.
authors: Doerte U
authors: DU
authors: Junghaenel
authors: Jules
authors: J
authors: Cohen
authors: Stefan
authors: S
authors: Schneider
authors: Anu R
authors: AR
authors: Neerukonda
authors: Joan E
authors: JE
authors: Broderick
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000503:physiopathology* / Q000523:psychology; D017024:Chemotherapy, Adjuvant; D003863:Depression / Q000523:psychology; D005221:Fatigue / Q000175:diagnosis* / Q000209:etiology*; D005260:Female; D006801:Humans; D008875:Middle Aged