title: Inflammation and behavioral symptoms after breast cancer treatment: do fatigue, depression, and sleep disturbance share a common underlying mechanism?
abstract: OBJECTIVE
  Fatigue, depression, and sleep disturbance are common adverse effects of cancer treatment and frequently co-occur. However, the possibility that inflammatory processes may underlie this constellation of symptoms has not been examined.
  
  
  METHODS
  Women (N = 103) who had recently finished primary treatment (ie, surgery, radiation, chemotherapy) for early-stage breast cancer completed self-report scales and provided blood samples for determination of plasma levels of inflammatory markers: soluble tumor necrosis factor (TNF) receptor II (sTNF-RII), interleukin-1 receptor antagonist, and C-reactive protein.
  
  
  RESULTS
  Symptoms were elevated at the end of treatment; greater than 60% of participants reported clinically significant problems with fatigue and sleep, and 25% reported elevated depressive symptoms. Women treated with chemotherapy endorsed higher levels of all symptoms and also had higher plasma levels of sTNF-RII than women who did not receive chemotherapy (all P < .05). Fatigue was positively associated with sTNF-RII, particularly in the chemotherapy-treated group (P < .05). Depressive symptoms and sleep problems were correlated with fatigue but not with inflammatory markers.
  
  
  CONCLUSIONS
  This study confirms high rates of behavioral symptoms in breast cancer survivors, particularly those treated with chemotherapy, and indicates a role for TNF-α signaling as a contributor to postchemotherapy fatigue. Results also suggest that fatigue, sleep disturbance, and depression may stem from distinct biologic processes in post-treatment survivors, with inflammatory signaling contributing relatively specifically to fatigue.
authors.affiliation: University of California, Los Angeles, Department of Psychology, 1285 Franz Hall, Los Angeles, CA 90095-1563, USA. jbower@ucla.edu
authors.forename: Julienne E
authors.initials: JE
authors.lastname: Bower
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Ganz
authors.forename: Michael R
authors.initials: MR
authors.lastname: Irwin
authors.forename: Lorna
authors.initials: L
authors.lastname: Kwan
authors.forename: Elizabeth C
authors.initials: EC
authors.lastname: Breen
authors.forename: Steve W
authors.initials: SW
authors.lastname: Cole
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000009:adverse effects; D015415:Biomarkers / Q000097:blood; D001943:Breast Neoplasms / Q000453:epidemiology / Q000628:therapy*; D002097:C-Reactive Protein / Q000378:metabolism; D002140:California / Q000453:epidemiology; D003131:Combined Modality Therapy / Q000009:adverse effects; D003863:Depression / Q000453:epidemiology / Q000209:etiology*; D005221:Fatigue / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000453:epidemiology*; D053590:Interleukin 1 Receptor Antagonist Protein / Q000097:blood; D008408:Mastectomy / Q000009:adverse effects; D008875:Middle Aged; D015999:Multivariate Analysis; D011878:Radiotherapy / Q000009:adverse effects; D047889:Receptors, Tumor Necrosis Factor, Type II / Q000097:blood; D012893:Sleep Wake Disorders / Q000453:epidemiology / Q000209:etiology*
chemical_list: D000970:Antineoplastic Agents; D015415:Biomarkers; D053590:Interleukin 1 Receptor Antagonist Protein; D047889:Receptors, Tumor Necrosis Factor, Type II; D002097:C-Reactive Protein