title: Lifetime and 5 years risk of breast cancer and attributable risk factor according to Gail model in Iranian women.
abstract: BACKGROUND
  Breast cancer is the most commonly diagnosed cancers in women worldwide and in Iran. It is expected to account for 29% of all new cancers in women at 2015. This study aimed to assess the 5 years and lifetime risk of breast cancer according to Gail model, and to evaluate the effect of other additional risk factors on the Gail risk.
  
  
  METHODS
  A cross sectional study conducted on 296 women aged more than 34-year-old in Qom, Center of Iran. Breast Cancer Risk Assessment Tool calculated the Gail risk for each subject. Data were analyzed by paired t-test, independent t-test, and analysis of variance in bivariate approach to evaluate the effect of each factor on Gail risk. Multiple linear regression models with stepwise method were used to predict the effect of each variable on the Gail risk.
  
  
  RESULTS
  The mean age of the participants was 47.8 ± 8.8-year-old and 47% have Fars ethnicity. The 5 years and lifetime risk was 0.37 ± 0.18 and 4.48 ± 0.925%, respectively. It was lower than the average risk in same race and age women (P < 0.001). Being single, positive family history of breast cancer, positive history of biopsy, and radiotherapy as well as using nonhormonal contraceptives were related to higher lifetime risk (P < 0.05). Moreover, a significant direct correlation observed between lifetime risk and body mass index, age of first live birth, and menarche age. While an inversely correlation observed between lifetimes risk of breast cancer and total month of breast feeding duration and age.
  
  
  CONCLUSIONS
  Based on our results, the 5 years and lifetime risk of breast cancer according to Gail model was lower than the same race and age. Moreover, by comparison with national epidemiologic indicators about morbidity and mortality of breast cancer, it seems that the Gail model overestimate the risk of breast cancer in Iranian women.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Health, Health Policy and Promotion Research Center, Qom University of Medical Sciences, Qom, Iran.
authors.forename: Abolfazl
authors.initials: A
authors.lastname: Mohammadbeigi
authors.affiliation: Department of Research Vice-chancellor, Qom University of Medical Sciences, Qom, Iran.
authors.forename: Narges
authors.initials: N
authors.lastname: Mohammadsalehi
authors.affiliation: Student Research Committee, Qom University of Medical Sciences, Qom, Iran.
authors.forename: Razieh
authors.initials: R
authors.lastname: Valizadeh
authors.affiliation: Student Research Committee, Qom University of Medical Sciences, Qom, Iran.
authors.forename: Zeinab
authors.initials: Z
authors.lastname: Momtaheni
authors.affiliation: Department Health Vice-Chancellor, Arak University of Medical Sciences, Arak, Iran.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Mokhtari
authors.affiliation: Health Promotion Research Center, Department of Epidemiology and biostatistics, Zahedan University of Medical Sciences, Zahedan, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Ansari
keywords: Breast cancer; Gail model; Iran; malignancy; predictor; risk factors