title: Death causes in breast cancer patients.
abstract: BACKGROUND
  Due to improved outcomes in breast cancer (BCa), the proportion of affected women dying of other causes has increased. Thus, a better survival of BCa requires knowledge of other causes of death.
  
  
  METHODS
  Data on the population, cancers, and causes of death were gathered from the nationwide Swedish Family-Cancer Database, enrolling ∼3.68 million Swedish women. A Cox regression model, comparing BCa patients against all other women, was applied. Cause-of-death-specific hazard ratios (HRs) were calculated for both underlying and multiple causes of death.
  
  
  RESULTS
  Among 641 000 deaths from 1987 to 2006, 48,000 were BCa patients. For underlying causes except BCa, the highest cause-specific HRs were found for diseases of pulmonary circulation {1.51 [95% confidence interval (CI) 1.36-1.68]}, suicide [1.39 (1.19-1.63)], and heart failure [1.29 (1.22-1.37)]. For specific multiple causes, the highest ratios were found for external causes [1.86 (1.80-1.91)] and gastrointestinal disease [1.68 (1.62-1.74)].
  
  
  CONCLUSIONS
  Diagnosis of BCa is associated with increased risks of dying of various causes, including external causes, heart failure, diseases of pulmonary circulation, and gastrointestinal disease. The study fulfills the gap in knowledge of death causes in BCa patients and suggests to draw more attention to comorbidities.
authors.affiliation: Division of Molecular Genetic Epidemiology, German Cancer Research Center, Heidelberg, Germany; Center for Primary Care Research, Lund University, Malmö, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Riihimäki
authors.affiliation: Division of Molecular Genetic Epidemiology, German Cancer Research Center, Heidelberg, Germany. Electronic address: h.thomsen@dkfz-heidelberg.de.
authors.forename: H
authors.initials: H
authors.lastname: Thomsen
authors.affiliation: Division of Molecular Genetic Epidemiology, German Cancer Research Center, Heidelberg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Brandt
authors.affiliation: Center for Primary Care Research, Lund University, Malmö, Sweden; Stanford Prevention Research Center, Stanford University School of Medicine, Stanford, USA.
authors.forename: J
authors.initials: J
authors.lastname: Sundquist
authors.affiliation: Division of Molecular Genetic Epidemiology, German Cancer Research Center, Heidelberg, Germany; Center for Primary Care Research, Lund University, Malmö, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Hemminki
mesh_terms: D001943:Breast Neoplasms / Q000150:complications / Q000401:mortality* / Q000473:pathology; D002423:Cause of Death; D005260:Female; D006801:Humans; D016016:Proportional Hazards Models; D012307:Risk Factors