title: Risk factors of breast cancer in north of Iran: a case-control in Mazandaran Province.
abstract: BACKGROUND
  Breast cancer is the most common cancer among Iranian women. This study aimed to determine risk factors for breast cancer in the north of Iran.
  
  
  METHODS
  A matched case-control study was conducted in Mazandaran province of Iran in 2004 of 250 biopsy proven cases of breast cancer and 500 neighbor controls that were matched by age within a 3 year period. Statistical analysis was carried out using conditional logistic regression with the backward elimination method and crude and adjusted odds ratios with related 95% CIs were estimated with Stata 8.0 software
  
  
  RESULTS
  Multivariate analysis showed that higher education (OR=4.70, 95%CI: 1.71-12.88), late menopause (OR=4.18, 95%CI: 2.54-6.88), history of induced abortion (OR=1.62, 95%CI: 1.13-2.31), positive first-degree family history of breast cancer (OR=3.14, 95%CI: 1.37-7.20), and BMI (OR=1.02, 95%CI: 1.01-1.03) were risk factors for breast cancer. Furthermore, having more episodes of full term pregnancy (OR=0.87, 95%CI: 0.80-0.95), longer duration of breast feeding (OR=0.993, 95%CI: 0.989-0.997) and parity more than 2 were shown to be protective factors.
  
  
  CONCLUSIONS
  Our study revealed the role of some modifiable determinants of breast cancer that can be focused by public health intervention in the northern community of Iran. Accordingly, the women who have one or more of the following risk factors should take the special attention to risk of breast cancer: obesity, being menopause, positive family history of breast cancer and history of induced abortion. The protective effect of longer duration of breast feeding should be encouraged too.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health and Institute of Public Health Research, Tehran University of Medical Sciences, Tehran, Iran. holakoik@hotmail.com
authors.forename: Kourosh Holakouie
authors.initials: KH
authors.lastname: Naieni
authors.forename: Ali
authors.initials: A
authors.lastname: Ardalan
authors.forename: Mahmood
authors.initials: M
authors.lastname: Mahmoodi
authors.forename: Abbas
authors.initials: A
authors.lastname: Motevalian
authors.forename: Yoosef
authors.initials: Y
authors.lastname: Yahyapoor
authors.forename: Bahareh
authors.initials: B
authors.lastname: Yazdizadeh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007492:Iran / Q000453:epidemiology; D016015:Logistic Models; D016555:Matched-Pair Analysis; D008875:Middle Aged; D015999:Multivariate Analysis; D012307:Risk Factors