Reproductive factors

Among reproductive factors, early menarche and late menopause, nulliparity and late first delivery, having few children and too short breast feeding time are implicated in the etiology of hormone dependent cancers (breast, ovary and uterine corpus). These factors, among other, increase the level of sex hormones in blood. Not only endogenous sex hormones but also exogenous (e.g. oral contraceptives and hormone replacement therapy of menopausal symptoms) increase the risk of these cancers, as well as obesity, especially after menopause.