title: Ovarian cancer and menopausal hormone therapy in the NIH-AARP diet and health study.
abstract: BACKGROUND
  Women using unopposed estrogens during menopause are at increased risk of ovarian cancer. It is uncertain whether oestrogen plus progestin therapy exerts similar effects.
  
  
  METHODS
  We evaluated menopausal hormone use and incident ovarian cancer (n=426) in 92601 post-menopausal women enrolled in the National Institutes of Health-AARP (NIH-AARP) Diet and Health Study. Participants were administered questionnaires in 1996-1997 and followed through 2006. Hazard rate ratios (RR) and 95% confidence intervals (CIs) were estimated using Cox regression.
  
  
  RESULTS
  Increased risks were associated with long duration (10+ years) use of unopposed oestrogen (RR 2.15, 95% CI: 1.30-3.57 among women with a hysterectomy) and oestrogen plus progestin (RR 1.68, 95% CI: 1.13-2.49 among women with intact uteri) therapy. Similar risks were associated with progestins that were used sequentially (<15 days progestin per month) (RR 1.60, 95% CI: 1.10-2.33) or continuously (>25 days progestin per month) (RR 1.43, 95% CI: 1.032-2.01; P-value for heterogeneity=0.63).
  
  
  CONCLUSIONS
  Our findings suggest that long duration use of both unopposed estrogens and oestrogen plus progestins are associated with increased risks of ovarian cancer, and that risk associated with oestrogen plus progestin use does not vary by regimen (sequential or continuous).
authors.affiliation: Department of Health and Human Services, Hormonal and Reproductive Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 6120 Executive Boulevard, Suite 550, Rockville, MD 20852, USA. britton.trabert@nih.gov
authors.forename: B
authors.initials: B
authors.lastname: Trabert
authors.forename: N
authors.initials: N
authors.lastname: Wentzensen
authors.forename: H P
authors.initials: HP
authors.lastname: Yang
authors.forename: M E
authors.initials: ME
authors.lastname: Sherman
authors.forename: A
authors.initials: A
authors.lastname: Hollenbeck
authors.forename: K N
authors.initials: KN
authors.lastname: Danforth
authors.forename: Y
authors.initials: Y
authors.lastname: Park
authors.forename: L A
authors.initials: LA
authors.lastname: Brinton
mesh_terms: D000368:Aged; D015331:Cohort Studies; D004032:Diet / Q000706:statistics & numerical data*; D015914:Estrogen Replacement Therapy / Q000009:adverse effects / Q000706:statistics & numerical data*; D004967:Estrogens / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009316:National Institutes of Health (U.S.); D010051:Ovarian Neoplasms / Q000139:chemically induced / Q000453:epidemiology*; D017698:Postmenopause; D011372:Progestins / Q000008:administration & dosage* / Q000009:adverse effects; D012306:Risk; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology
chemical_list: D004967:Estrogens; D011372:Progestins