title: Parity and Oral Contraceptive Use in Relation to Ovarian Cancer Risk in Older Women.
abstract: Several studies have suggested that the ovarian cancer risk reductions associated with parity and oral contraceptive use are weaker in postmenopausal than premenopausal women, yet little is known about the persistence of these reductions as women age. This question gains importance with the increasing numbers of older women in the population.
  
  
  
  We addressed the question using data from three large U.S. cohort studies involving 310,290 white women aged 50+ years at recruitment, of whom 1,815 developed subsequent incident invasive epithelial ovarian cancer. We used Cox regression, stratified by cohort, to examine age-related trends in the HRs per full-term pregnancy and per year of oral contraceptive use.
  
  
  
  The parity-associated risk reductions waned with age (Ptrend < 0.001 in HR with increasing age), particularly among women aged 75 years or more, for whom we observed no association with parity. However, we observed no such attenuation in the oral contraceptive-associated risk reductions (P = 0.79 for trend in HR with increasing age).
  
  
  
  These findings suggest that prior oral contraceptive use is important for ovarian cancer risk assessment among women of all ages, while the benefits of parity wane as women age.
  
  
  
  This information, if duplicated in other studies, will be useful to preventive counseling and risk prediction, particularly for women at increased ovarian cancer risk due to a personal history of breast cancer or a family history of ovarian cancer. Cancer Epidemiol Biomarkers Prev; 25(7); 1059-63. ©2016 AACR.
authors.affiliation: Division of Epidemiology, Department of Health Research and Policy, Stanford University School of Medicine, Stanford, California.
authors.forename: Valerie
authors.initials: V
authors.lastname: McGuire
authors.affiliation: Division of Cancer Epidemiology and Biostatistics, NCI, Bethesda, Maryland.
authors.forename: Patricia
authors.initials: P
authors.lastname: Hartge
authors.affiliation: Division of Cancer Epidemiology and Genetics, Nutritional Epidemiology Branch, NCI, Bethesda, Maryland.
authors.forename: Linda M
authors.initials: LM
authors.lastname: Liao
authors.affiliation: Division of Cancer Epidemiology and Genetics, Nutritional Epidemiology Branch, NCI, Bethesda, Maryland.
authors.forename: Rashmi
authors.initials: R
authors.lastname: Sinha
authors.affiliation: Division of Cancer Etiology, Department of Population Sciences, City of Hope National Medical Center and Comprehensive Cancer Center, Duarte, California.
authors.forename: Leslie
authors.initials: L
authors.lastname: Bernstein
authors.affiliation: Cancer Prevention Institute of California, Fremont, California.
authors.forename: Alison J
authors.initials: AJ
authors.lastname: Canchola
authors.affiliation: Fred Hutchinson Cancer Research Center, Public Health Sciences Division Cancer Prevention, University of Washington School of Public Health and Community Medicine, Seattle, Washington.
authors.forename: Garnet L
authors.initials: GL
authors.lastname: Anderson
authors.affiliation: Department of Medicine, Stanford Prevention Research Center, Stanford University School of Medicine, Stanford, California.
authors.forename: Marcia L
authors.initials: ML
authors.lastname: Stefanick
authors.affiliation: Division of Epidemiology, Department of Health Research and Policy, Stanford University School of Medicine, Stanford, California. alicesw@stanford.edu.
authors.forename: Alice S
authors.initials: AS
authors.lastname: Whittemore
mesh_terms: D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D000375:Aging; D000077216:Carcinoma, Ovarian Epithelial; D015331:Cohort Studies; D003276:Contraceptives, Oral / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009375:Neoplasms, Glandular and Epithelial / Q000453:epidemiology*; D010051:Ovarian Neoplasms / Q000453:epidemiology*; D010298:Parity; D011247:Pregnancy; D016016:Proportional Hazards Models; D012307:Risk Factors
chemical_list: D003276:Contraceptives, Oral