Progestogen use in women approaching the menopause and breast cancer risk.

Objective: Progestogens, particularly synthetic progestins, are widely used to contrast the clinical consequences of the relative hyperestrogenism that characterizes the years preceding the menopause. As a large body of data on postmenopausal hormone therapy (HT) demonstrates that the addition of synthetic progestins to estrogen increases the breast cancer risk compared to estrogen alone, it is important to evaluate if the use of progestogens in premenopausal years is associated with the risk of breast cancer.

Methods: Main literature data on the association with breast cancer risk of progestogens, either used alone in premenopausal years or added to estrogen in postmenopausal HT, were reviewed.