title: The influence of comorbidity on mortality in ovarian cancer patients.
abstract: BACKGROUND
  Ovarian cancer is a severe disease with a peak incidence in the older age groups where concurrent morbidity is common and could potentially influence mortality rates.
  
  
  OBJECTIVE
  The aim was to study the influence of common comorbidity diagnoses on mortality in ovarian cancer patients.
  
  
  METHODS
  The study population was patients with ovarian cancer in Sweden 1993-2006 (n=11.139) identified in the national Cancer Register. Comorbidity data was obtained from the Patient Register and mortality from Cause of Death Register. Mortality was analyzed with Cox' proportional hazards models and subgroup analyses were performed by age and tumor histology.
  
  
  RESULTS
  Almost all of the assessed comorbidities increased mortality in ovarian cancer patients. Thromboembolism was the most hazardous comorbidity (HR=1.95, <1 year after cancer diagnosis and HR=7.83, 1-5 years after cancer diagnosis) followed by hematologic complications (HR=1.84 and 7.11 respectively) and infectious disease (HR=1.48 and 5.28 respectively). The occurrence of diabetes mellitus and hypertension had less impact on mortality.
  
  
  CONCLUSIONS
  Thromboembolism, hematologic complications and infections had a pronounced effect on mortality rates in women with ovarian cancer. The impact of comorbidity was mainly apparent among those with a more prosperous prognosis, such as longer time since cancer diagnosis, less aggressive tumors and younger age.
authors.affiliation: Department of Women's and Children's Health, Uppsala University, 75185 Uppsala, Sweden. Electronic address: karin.stalberg@kbh.uu.se.
authors.forename: K
authors.initials: K
authors.lastname: Stålberg
authors.affiliation: Centre for Pharmacoepidemiology, Department of Medicine, Karolinska Institutet, 17177 Stockholm, Sweden.
authors.forename: T
authors.initials: T
authors.lastname: Svensson
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, 17177 Stockholm, Sweden; Research and Development, Region Halland, 30185 Halmstad, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Lönn
authors.affiliation: Centre for Pharmacoepidemiology, Department of Medicine, Karolinska Institutet, 17177 Stockholm, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Kieler
mesh_terms: D000368:Aged; D000077216:Carcinoma, Ovarian Epithelial; D003141:Communicable Diseases / Q000453:epidemiology*; D015897:Comorbidity; D003920:Diabetes Mellitus / Q000453:epidemiology; D005260:Female; D006402:Hematologic Diseases / Q000453:epidemiology*; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D008875:Middle Aged; D009373:Neoplasms, Germ Cell and Embryonal / Q000453:epidemiology* / Q000401:mortality; D009375:Neoplasms, Glandular and Epithelial / Q000453:epidemiology* / Q000401:mortality; D010051:Ovarian Neoplasms / Q000453:epidemiology* / Q000401:mortality; D011379:Prognosis; D016016:Proportional Hazards Models; D012307:Risk Factors; D012509:Sarcoma / Q000453:epidemiology* / Q000401:mortality; D018312:Sex Cord-Gonadal Stromal Tumors / Q000453:epidemiology* / Q000401:mortality; D013548:Sweden / Q000453:epidemiology; D013923:Thromboembolism / Q000453:epidemiology*
keywords: Comorbidity; Epidemiology; Mortality; Ovarian cancer