title: Presence of symptom clusters in surgically treated patients with esophageal cancer: implications for survival.
abstract: BACKGROUND
  It is not known whether symptoms cluster together after esophageal cancer surgery or whether such symptom clusters are associated with survival in patients with esophageal cancer who are treated surgically.
  
  
  METHODS
  Data from a prospective Swedish nationwide cohort study of surgically treated patients with esophageal cancer recruited between 2001 and 2005 were used. General and esophageal cancer-specific symptoms were assessed using the European Organization for Research and Treatment of Cancer QLQ-C30 quality of life questionnaire and the QLQ-OES18 module at 6 months after surgery. Associations between symptom clusters and survival were analyzed using Cox proportional hazards models, providing hazards ratios with 95% confidence intervals, adjusted for other known prognostic factors.
  
  
  RESULTS
  Among 402 patients reporting symptoms 6 months after surgery, 3 symptom clusters were identified. The first symptom cluster (“fatigue/pain”) was characterized by symptoms of pain, fatigue, insomnia, and dyspnea and was present in 30% of patients. The second symptom cluster (“reflux/cough”) was characterized by symptoms of dry mouth, problems with taste, coughing, and reflux and was present in 27% of patients. The third symptom cluster (“eating difficulties”) was characterized by appetite loss, dysphagia, eating difficulties, and nausea/vomiting and was present in 28% of patients. The presence of the reflux/cough and eating difficulties symptom clusters was associated with a statistically significantly increased risk of mortality (adjusted hazards ratio, 1.43 [95% confidence interval, 1.08-1.89] and adjusted HR, 1.41 [95% confidence interval, 1.06-1.87], respectively).
  
  
  CONCLUSIONS
  Symptoms experienced by surgically treated patients with esophageal cancer appear to cluster together, and the presence of these symptom clusters appears to have strong prognostic value.
authors.forename: Anna
authors.initials: A
authors.lastname: Wikman
authors.forename: Asif
authors.initials: A
authors.lastname: Johar
authors.forename: Pernilla
authors.initials: P
authors.lastname: Lagergren
mesh_terms: D000368:Aged; D003371:Cough / Q000209:etiology; D003680:Deglutition Disorders / Q000209:etiology; D004417:Dyspnea / Q000209:etiology; D004938:Esophageal Neoplasms / Q000209:etiology* / Q000401:mortality* / Q000601:surgery*; D005221:Fatigue / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011795:Surveys and Questionnaires