title: Fatigue in people with localized colorectal cancer who do and do not receive chemotherapy: a longitudinal prospective study.
abstract: Fatigue is associated with cancer and chemotherapy and may be sustained. Here, we describe a prospective longitudinal study evaluating fatigue and putative mechanisms in people with colorectal cancer (CRC).
  
  
  
  People with localized CRC completed the Functional Assessment of Cancer Treatment-Fatigue (FACT-F) questionnaire at baseline (before chemotherapy, if given), 6, 12, and 24 months. Healthy controls (HCs) were assessed at the first three time points. Fatigue was defined by standardized FACT-F scores ≤68/100. Quality-of-life (QoL, assessed by the FACT-G questionnaire), affective, and cognitive symptoms were evaluated. Associations were sought between fatigue, baseline factors, and blood tests (including hemoglobin, cytokines, and sex hormones). Regression analyses, Fisher's exact tests, and Wilcoxon rank-sum tests assessed levels of fatigue at each time point and change in fatigue from baseline. A repeated-measures analysis investigated prognostic factors of fatigue across all time points.
  
  
  
  A total of 289 subjects with localized CRC (173 received chemotherapy) and 72 HCs were assessed. More CRC patients had fatigue than HCs at baseline (52% versus 26%, P < 0.001). Fatigue was increased in the chemotherapy (CTh) group at 6 months [CTh+ 70% versus CTh- 31% (P < 0.001), HCs 22%] and remained more common at 12 [CTh+ 44% versus CTh- 31% (P = 0.079)] and 24 months [CTh+ 39% versus CTh- 24% (P = 0.047)]. There was no significant difference between those not receiving chemotherapy and HCs at follow-up assessments. Fatigue was associated with poor QoL, affective and cognitive symptoms, but not consistently with cytokine levels. Predictors for sustained fatigue were baseline fatigue, treatment group, cognitive and affective symptoms, poorer QoL, and comorbidities.
  
  
  
  CRC patients have more fatigue than HCs at baseline. Fatigue peaks immediately after adjuvant chemotherapy, but remains common for 2 years in those who receive chemotherapy. Cognitive and affective symptoms, QoL, comorbidities, chemotherapy, and baseline fatigue predict for longer term fatigue.
authors.affiliation: Sydney Medical School, University of Sydney, Sydney, Australia Princess Margaret Cancer Centre, University of Toronto, Toronto, Canada Concord Cancer Centre, Concord Hospital, Concord, Australia janette.vardy@sydney.edu.au.
authors.forename: J L
authors.initials: JL
authors.lastname: Vardy
authors.affiliation: Sydney Medical School, University of Sydney, Sydney, Australia.
authors.forename: H M
authors.initials: HM
authors.lastname: Dhillon
authors.affiliation: Department of Oncology, McMaster University, Hamilton.
authors.forename: G R
authors.initials: GR
authors.lastname: Pond
authors.affiliation: Sydney Medical School, University of Sydney, Sydney, Australia.
authors.forename: C
authors.initials: C
authors.lastname: Renton
authors.affiliation: Princess Margaret Cancer Centre, University of Toronto, Toronto, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Dodd
authors.affiliation: St Michael's Hospital, University of Toronto, Toronto, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Sydney Medical School, University of Sydney, Sydney, Australia.
authors.forename: S J
authors.initials: SJ
authors.lastname: Clarke
authors.affiliation: Princess Margaret Cancer Centre, University of Toronto, Toronto, Canada.
authors.forename: I F
authors.initials: IF
authors.lastname: Tannock
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000009:adverse effects; D017024:Chemotherapy, Adjuvant / Q000009:adverse effects*; D015179:Colorectal Neoplasms / Q000150:complications / Q000188:drug therapy* / Q000453:epidemiology / Q000473:pathology; D005221:Fatigue / Q000139:chemically induced / Q000453:epidemiology / Q000473:pathology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D011795:Surveys and Questionnaires
keywords: cancer-related fatigue; chemotherapy; colorectal cancer; quality of life