Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 27 1-2 1998 03 15 61 70 M.Alavi Naini K. Gholami 2015 10 03 Second to the cardiovascular disease, cancer is the main cause of death in Iran. In this study some of the risk factors of breast cancer; especially the ones related to breastfeeding have been assessed. The study was a retrospective study of 100 women with breast cancer. The most important risk factors in breast cancer were number of children, age of mother on the first pregnancy. The result showed that the increase of breast cancer was related to women who stopped breastfeeding before age 24 months. Breastfeeding for more than 12 months will reduce the incidence of breast cancer by 25%. In general there was a reverse relationship between duration of breastfeeding and risk of cancer in premonopausal, but not in postmenopausal women. https://ijph.tums.ac.ir/index.php/ijph/article/view/1775 https://ijph.tums.ac.ir/index.php/ijph/article/download/1775/1756