Breast Cancer Prevention: Lessons to be Learned from Mechanisms of Early Pregnancy–Mediated Breast Cancer Protection

Pregnancy at early, but not late age, has a strong and life-long protective effect against breast cancer. The expected overall increase in breast cancer incidence demands the development of a pharmaceutical mimicry of early-age pregnancy-mediated protection. Recently, converging results from rodent models and women on molecular and cellular mechanisms underlying the protective effect of early-age pregnancy have opened the door for translational studies on pharmacologic prevention against breast cancer. In particular, alterations in Wnt and TGFbeta signaling in mammary stem/progenitor cells reveal new potential targets for preventive interventions, and thus might help to significantly reduce the incidence of breast cancer in the future.