title: Cancer-related fatigue: epidemiology, pathogenesis, diagnosis, and treatment.
abstract: BACKGROUND
  Many cancer patients suffer from cancer-related fatigue (CRF) both during and after their treatment. CRF can arise at any point in the course of the disease and can be either self-limited or persistent, sometimes for years. It gives rise to a vicious circle of impaired physical performance, avoidance of exertion, inactivity, inadequate physical recovery, helplessness, and depressed mood. Its hallmarks are tiredness, exhaustion, and lack of energy; it can impair performance so severely that the patient is unable to work. It is associated with increased mortality. Cancer patients are hardly ever systematically asked about the symptoms and signs of CRF. The stress and impairments that it produces are often inadequately appreciated, and the opportunities for treatment often neglected.
  
  
  METHODS
  Selective review of the pertinent literature, including published guidelines from Germany and abroad.
  
  
  RESULTS
  The pathogenesis of CRF is complex, involving an interaction of somatic, emotional, cognitive, and psychosocial factors, with a highly variable pattern of clinical expression. Clinical history-taking plays a key role in diagnostic assessment. Depressive disorders must be considered in the differential diagnosis. Many randomized trials and meta-analyses have documented the efficacy of pharmacological and non-pharmacological treatments for CRF.
  
  
  CONCLUSIONS
  Cancer-related fatigue is a serious problem that impairs patients physically, mentally, and socially. Physicians need to know how to recognize and treat it.
authors.affiliation: Medical Clinic 5-Nuremberg Hospital: Internal Medicine, Oncology, Hematology, Germany. horneber@klinikum-nuernberg.de
authors.forename: Markus
authors.initials: M
authors.lastname: Horneber
authors.forename: Irene
authors.initials: I
authors.lastname: Fischer
authors.forename: Fernando
authors.initials: F
authors.lastname: Dimeo
authors.forename: Jens Ulrich
authors.initials: JU
authors.lastname: Rüffer
authors.forename: Joachim
authors.initials: J
authors.lastname: Weis
mesh_terms: D015984:Causality; D015897:Comorbidity; D005221:Fatigue / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy*; D005858:Germany / Q000453:epidemiology; D006801:Humans; D009369:Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy*; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors; D016019:Survival Analysis; D015996:Survival Rate