title: Oral contraceptives, abortion and breast cancer risk: a case control study in Saudi Arabia.
abstract: BACKGROUND
  Several studies have examined the relationship between oral contraceptive pill (OCP) use, abortions and breast cancer, with mixed results. Hormonal changes associated with OCP use and abortion may increase risk of breast cancer over time, but there is a lack of studies studying this association in Saudi Arabian women.
  
  
  METHODS
  We thererfore conducted a case control study in 192 women (92 as cases and 100 as controls), aged 30 to 65, and collected information on variables including examples related to study objectives and those which may confound findings. The Chi square test was used to detect associations between various factors and risk of breast cancer.
  
  
  RESULTS
  We found no evidence of interaction between history of abortion or frequency of abortion and breast cancer risk (Chi square=0.422, p =0.420 and 1, p =0.169) respectively. Oral contraceptives did not confer risk for breast cancer overall (OR=0.276, 95%CI 0.092-0.829, p=0.524), while long term use of OCP was associated with increased risk of breast cancer (OR=0.297, 95%CI 0.158-0.557, p=0.001), with higher association for those who used 10 years or more of OCPs (OR=0.282, 95%CI 0.095-0.835, p=0.02). Age at first use of OCPs had no effect on breast cancer risk (p=0.452) or age at diagnosis (p=0.074).
  
  
  CONCLUSIONS
  Prolonged use of OC (more than 10 years) may be associated with increased risk of breast cancer in Saudi women. Larger population based studies are needed to confirm this finding in this population.
authors.affiliation: Department of Oncology, King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia E-mail : skarim@kfshrc.edu.sa.
authors.forename: Syed Mustafa
authors.initials: SM
authors.lastname: Karim
authors.forename: Wijdan
authors.initials: W
authors.lastname: Baeshen
authors.forename: Syed Nehal
authors.initials: SN
authors.lastname: Neamatullah
authors.forename: Bakr
authors.initials: B
authors.lastname: Bin
mesh_terms: D000028:Abortion, Induced; D000022:Abortion, Spontaneous; D001943:Breast Neoplasms / Q000139:chemically induced* / Q000453:epidemiology*; D016022:Case-Control Studies; D003276:Contraceptives, Oral / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D011379:Prognosis; D012307:Risk Factors; D012529:Saudi Arabia / Q000453:epidemiology; D013997:Time Factors
chemical_list: D003276:Contraceptives, Oral