title: Hormonal and surgical treatments for endometriosis and risk of epithelial ovarian cancer.
abstract: OBJECTIVE
  Whether hormonal or surgical treatment of endometriosis is associated with risk of epithelial ovarian cancer.
  
  
  METHODS
  Nested case-control study.
  
  
  METHODS
  Sweden.
  
  
  METHODS
  All women with a first-time discharge diagnosis of endometriosis in 1969-2007 were identified using the National Swedish Patient Register and constituted our study base.
  
  
  METHODS
  By linkage to the National Swedish Cancer Register we identified all women diagnosed with epithelial ovarian cancer at least one year after the endometriosis diagnosis (cases). Two controls per case with no ovarian cancer before the date of cancer diagnosis of the case were randomly selected from the study base and matched for year of birth. Two-hundred-and-twenty cases and 416 controls entered the study. Information on hormonal and surgical treatments and other reproductive factors was extracted from medical records according to pre-specified protocols. Conditional logistic regression was used for all calculations.
  
  
  METHODS
  Crude and adjusted odds ratios (OR) with 95% confidence intervals (CI) for all hormonal as well as surgical treatments.
  
  
  RESULTS
  There was a significant association between one-sided oophorectomy, as well as for radical extirpation of all visible endometriosis, and ovarian cancer risk in both univariate analyses (crude OR 0.42, 95% CI 0.28-0.62 and OR 0.37, 95% CI 0.25-0.55, respectively) and multivariate analyses (adjusted OR 0.19, 95% CI 0.08-0.46 and OR 0.30, 95% CI 0.12-0.74, respectively).
  
  
  CONCLUSIONS
  One-sided oophorectomy as well as radical extirpation of all visible endometriosis is protective against later development of ovarian cancer.
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm, Sweden. anna-sofia.melin@aleris.se
authors.forename: Anna-Sofia
authors.initials: AS
authors.lastname: Melin
authors.forename: Cecilia
authors.initials: C
authors.lastname: Lundholm
authors.forename: Ninoa
authors.initials: N
authors.lastname: Malki
authors.forename: Marja-Liisa
authors.initials: ML
authors.lastname: Swahn
authors.forename: Pär
authors.initials: P
authors.lastname: Sparèn
authors.forename: Agneta
authors.initials: A
authors.lastname: Bergqvist
mesh_terms: D000328:Adult; D000368:Aged; D000077216:Carcinoma, Ovarian Epithelial; D016022:Case-Control Studies; D004715:Endometriosis / Q000150:complications / Q000188:drug therapy / Q000601:surgery*; D005260:Female; D006728:Hormones / Q000627:therapeutic use; D006801:Humans; D008875:Middle Aged; D009375:Neoplasms, Glandular and Epithelial / Q000453:epidemiology* / Q000209:etiology; D016017:Odds Ratio; D010051:Ovarian Neoplasms / Q000453:epidemiology* / Q000209:etiology; D010052:Ovariectomy / Q000379:methods; D012042:Registries; D018570:Risk Assessment; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult
chemical_list: D006728:Hormones