title: Parity, infertility, oral contraceptives, and hormone replacement therapy and the risk of ovarian serous borderline tumors: A nationwide case-control study.
abstract: Few studies have examined the risk of an ovarian serous borderline tumor (SBT) associated with parity, infertility, oral contraceptives (OCs), or hormone replacement therapy (HRT), which was the study aim.
  
  
  
  This nationwide case-control study included all women with an SBT diagnosis in Denmark, 1978-2002. SBTs were confirmed by centralized expert pathology review. For each case, 15 age-matched female controls were randomly selected using risk-set sampling. Cases and controls with previous cancer (except for non-melanoma skin cancer) and controls with bilateral oophorectomy or salpingo-oophorectomy were excluded. Conditional logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs).
  
  
  
  We found a strongly decreased risk of SBTs among parous women which decreased with increasing number of children (p<0.01). Older age at first birth also decreased the SBT risk (p=0.03). An increased SBT risk was associated with infertility (OR=3.31; 95% CI: 2.44-4.49), which was present both among parous and nulliparous women. HRT use increased the SBT risk (OR=1.32; 95% CI: 1.02-1.72), whereas OC use decreased the risk (OR=0.40; 95% CI: 0.26-0.62).
  
  
  
  Our nationwide study with expert histopathologic review of all SBTs showed that parity, infertility, use of HRT, and use of OCs, respectively, were strongly associated with the risk of SBTs. This is the first study to report a strong and significantly decreased SBT risk associated with OC use and a significantly increased risk with infertility, and HRT use. This supports that SBTs and serous ovarian cancer share similar risk factors.
authors.affiliation: Unit of Virus, Lifestyle and Genes, Danish Cancer Society Research Center, Strandboulevarden 49, 2100 Copenhagen, Denmark.
authors.forename: Emma L Kaderly
authors.initials: ELK
authors.lastname: Rasmussen
authors.affiliation: Unit of Virus, Lifestyle and Genes, Danish Cancer Society Research Center, Strandboulevarden 49, 2100 Copenhagen, Denmark.
authors.forename: Charlotte Gerd
authors.initials: CG
authors.lastname: Hannibal
authors.affiliation: Unit of Statistics, Bioinformatics and Registry, Danish Cancer Society Research Center, Strandboulevarden 49, 2100 Copenhagen, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Dehlendorff
authors.affiliation: Unit of Virus, Lifestyle and Genes, Danish Cancer Society Research Center, Strandboulevarden 49, 2100 Copenhagen, Denmark.
authors.forename: Louise
authors.initials: L
authors.lastname: Baandrup
authors.affiliation: Department of Pathology, Hvidovre Hospital, Kettegård Allé 30, 2650 Hvidovre, Denmark.
authors.forename: Jette
authors.initials: J
authors.lastname: Junge
authors.affiliation: Departments of Pathology, Gynecology and Obstetrics, The Johns Hopkins University School of Medicine, 401 North Broadway, Baltimore, MD 21231, USA.
authors.forename: Russell
authors.initials: R
authors.lastname: Vang
authors.affiliation: Departments of Gynecology/Obstetrics, Pathology and Oncology, The Johns Hopkins University School of Medicine, 401 North Broadway, Baltimore, MD 21231, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Kurman
authors.affiliation: Unit of Virus, Lifestyle and Genes, Danish Cancer Society Research Center, Strandboulevarden 49, 2100 Copenhagen, Denmark; Department of Gynecology, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen, Denmark. Electronic address: susanne@cancer.dk.
authors.forename: Susanne K
authors.initials: SK
authors.lastname: Kjaer
mesh_terms: D000328:Adult; D000077216:Carcinoma, Ovarian Epithelial; D016022:Case-Control Studies; D003276:Contraceptives, Oral / Q000008:administration & dosage*; D018284:Cystadenocarcinoma, Serous / Q000175:diagnosis / Q000453:epidemiology*; D003718:Denmark / Q000453:epidemiology; D005260:Female; D020249:Hormone Replacement Therapy / Q000706:statistics & numerical data*; D006801:Humans; D007246:Infertility / Q000453:epidemiology*; D009375:Neoplasms, Glandular and Epithelial / Q000175:diagnosis / Q000453:epidemiology*; D010051:Ovarian Neoplasms / Q000175:diagnosis / Q000453:epidemiology*; D010298:Parity; D012307:Risk Factors; D055815:Young Adult
chemical_list: D003276:Contraceptives, Oral
keywords: Hormone replacement therapy (HRT); Infertility; Oral contraceptive (OC); Ovarian serous borderline tumor (SBT); Parity; Risk factor