title: Ovarian cancer in the United States: contemporary patterns of care associated with improved survival.
abstract: BACKGROUND
  Ovarian cancer (OC) requires complex multidisciplinary care with wide variations in outcome. We sought to determine the impact of institutional and process of care factors on overall survival (OS) and delivery of guideline care nationally.
  
  
  METHODS
  This was a retrospective cohort study of primary OC diagnosed from 1998 to 2007 using the National Cancer Data Base (NCDB) capturing 80% of all U.S. cases. Patient- (demographics, comorbidities, stage/grade), process of care (adherence to guidelines) and institutional- (facility type, case volume) factors were evaluated. Primary outcomes were OS and delivery of guideline therapy. Multivariable logistic regression and Cox proportional hazards models were used for analysis.
  
  
  RESULTS
  We analyzed 96,802 consecutive cases. Five-year OS was 84%, 66.3%, 32% and 15.7% for stages I, II, III and IV, respectively. The annual mean facility case volumes varied by cancer center type (range: 5.7 to 26.7), with 25% of cases spread over 65% of centers--all treating fewer than 8 cases. Overall, 56% of cases received non-guideline care. Low facility case volume and higher comorbidity index independently predicted non-guideline care; high volume centers were less likely to deliver non-guideline care (OR: 0.44, 95% CI: 0.41-0.47). Delivery of non-guideline care (OR: 1.4, 95% CI: 1.36-1.44), and higher facility case volume (OR: 0.91, 95% CI: 0.86-0.96) were both independent predictors of OS.
  
  
  CONCLUSIONS
  Delivery of guideline care and facility case volume are important drivers of overall survival. Most cancer centers treat very few women with OC. National efforts should focus on improved access to centers with expertise in OC and ensuring delivery of guideline care.
authors.affiliation: Mayo Clinic, Rochester, MN 55905, USA. Electronic address: Cliby.william@mayo.edu.
authors.forename: William A
authors.initials: WA
authors.lastname: Cliby
authors.affiliation: Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, USA.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Powell
authors.affiliation: Division of Biostatistics, Washington University School of Medicine, USA.
authors.forename: Noor
authors.initials: N
authors.lastname: Al-Hammadi
authors.affiliation: Division of Biostatistics, Washington University School of Medicine, USA.
authors.forename: Ling
authors.initials: L
authors.lastname: Chen
authors.affiliation: Division of Biostatistics, Washington University School of Medicine, USA.
authors.forename: J
authors.initials: J
authors.lastname: Philip Miller
authors.affiliation: Gynecologic Oncology, Department of Gynecology and Obstetrics, Saint Francis Hospital and Medical Center, USA.
authors.forename: Phillip Y
authors.initials: PY
authors.lastname: Roland
authors.affiliation: Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, USA.
authors.forename: David G
authors.initials: DG
authors.lastname: Mutch
authors.affiliation: Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, University of California, Irvine School of Medicine, USA.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Bristow
mesh_terms: D000368:Aged; D015331:Cohort Studies; D005260:Female; D019983:Guideline Adherence / Q000706:statistics & numerical data; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D010051:Ovarian Neoplasms / Q000401:mortality* / Q000473:pathology / Q000628:therapy*; D012189:Retrospective Studies; D014481:United States / Q000453:epidemiology
keywords: Cancer center; Care patterns; Ovarian cancer; Survival; United States; Volume