Combined oral contraceptive use before the first birth and epithelial ovarian cancer risk. Academic Article uri icon

start page

  • 265

end page

  • 269


  • Combined oral contraceptive (COC) use reduces epithelial ovarian cancer (EOC) risk. However, little is known about risk with COC use before the first full-term pregnancy (FFTP).This Canadian population-based case-control study (2001-2012) included 854 invasive cases/2139 controls aged ⩾40 years who were parous and had information on COC use. We estimated odds ratios (aORs) and 95% confidence intervals (CI) adjusted for study site, age, parity, breastfeeding, age at FFTP, familial breast/ovarian cancer, tubal ligation, and body mass.Among parous women, per year of COC use exclusively before the FFTP was associated with a 9% risk reduction (95% CI=0.86-0.96). Results were similar for high-grade serous and endometrioid/clear cell EOC. In contrast, per year of use exclusively after the FFTP was not associated with risk (aOR=0.98, 95% CI=0.95-1.02).Combined oral contraceptive use before the FFTP may provide a risk reduction that remains for many years, informing possible prevention strategies.

date/time value

  • January 2017

Digital Object Identifier (DOI)

  • 10.1038/bjc.2016.400

PubMed Identifier

  • 27959890


  • 116


  • 2


  • Adult
  • Aged
  • Birth Order
  • Breast Neoplasms
  • Canada
  • Case-Control Studies
  • Contraceptives, Oral, Combined
  • Female
  • Humans
  • Middle Aged
  • Neoplasms, Glandular and Epithelial
  • Ovarian Neoplasms
  • Parity
  • Pregnancy
  • Risk Factors
  • Sterilization, Tubal
  • Young Adult