title: Breast cancer risk factors in Turkey: a hospital-based case-control study.
abstract: BACKGROUND
  Regional disparities in breast cancer (BC) outcomes have been reported in Turkey.
  
  
  METHODS
  In a hospital-based case-control study in Sivas, Turkey, 172 patients with histologically confirmed BC were compared with 383 controls, recruited from visitors in various departments of the same hospital, who had not been previously diagnosed with BC. Information was collected from both groups using a questionnaire and logistic regression analysis was applied to assess associations between each risk factor and BC risk with adjusted odds ratios (ORs) and 95% confidence intervals (CIs).
  
  
  RESULTS
  In multivariable models, family history of BC (OR=4.67, 95% CI: 2.23-9.76), history of smoking (OR=1.75, 95% CI: 1.08-2.84), and higher education level (OR=2.88, 95% CI: 1.64-5.07) were the strongest predictors of BC in the study population. A separate analysis studying only postmenopausal women using hormone replacement therapy (HRT) (comparing duration of use, >36 months versus ≤36 months, P<0.05) found that use of HRT was also a risk factor for BC. Duration of HRT use (P<0.05) was significantly associated with the elevated risk. On the other hand, certain factors such as first full-term pregnancy before age 30 (χ2=5.755 P<0.05) and higher parity (χ2=20.731, P<0.05) were found to be protective factors for BC.
  
  
  CONCLUSIONS
  The findings of the present study indicate that family history of BC, history of smoking, education, and HRT are factors significantly associated with increased BC risk among Turkish women within the area of Central Anatolia, Turkey.
authors.affiliation: Biostatistics Department, Medical Faculty, Cumhuriyet University, Sivas, Turkey.
authors.forename: Hafize
authors.initials: H
authors.lastname: Sezer
authors.forename: Meryem
authors.initials: M
authors.lastname: Yilmaz
authors.forename: Hesna
authors.initials: H
authors.lastname: Gurler
authors.forename: Ayhan
authors.initials: A
authors.lastname: Koyuncu
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology; D016022:Case-Control Studies; D016001:Confidence Intervals; D003906:Developing Countries; D004522:Educational Status; D005260:Female; D020249:Hormone Replacement Therapy / Q000009:adverse effects / Q000706:statistics & numerical data; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D016017:Odds Ratio; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D011795:Surveys and Questionnaires; D014421:Turkey / Q000453:epidemiology