RÉSUMÉ
Context: Breast cancer is the most common cancer in women worldwide and its prevalence is increasing. Aims: The aim of this study was to investigate the extent to which a history of infertility can present as risk factors for breast cancer. Settings and Design: This was a hospital-based case–control study. Subjects and Methods: In this study, 1177 women with breast cancer were participated for assessing the risk for this cancer. The control was 1204 women with self-reported free-cancer history who were matched in terms of age and residence. Statistical Analysis Used: Using logistic regression, it was examined whether infertility is a risk factor of case–control status in addition to marriage age, menarche age, body mass index, number of pregnancies, family history of breast cancer, and previous oral contraceptive use. The data were considered significant at P ≤ 0.05. Results: Infertility history was reported in 12.5% (n = 147) of the cases and 5.8% (n = 70) of the controls. Infertility history was a relevant risk for case–control study in addition to other risk factors (odds ratio: 2.43; 95% confidence interval, 3.34–1.77). Conclusions: This study found that infertility may be as the main risk factor for breast cancer in Iranian women, therefore, doing breast screening in women who have one or more risk factors, must receive more emphasis