AUTHOR=Katz Tiffany A. TITLE=Potential Mechanisms underlying the Protective Effect of Pregnancy against Breast Cancer: A Focus on the IGF Pathway JOURNAL=Frontiers in Oncology VOLUME=6 YEAR=2016 URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2016.00228 DOI=10.3389/fonc.2016.00228 ISSN=2234-943X ABSTRACT=

A first full-term birth at an early age protects women against breast cancer by reducing lifetime risk by up to 50%. The underlying mechanism resulting in this protective effect remains unclear, but many avenues have been investigated, including lobular differentiation, cell fate, and stromal composition. A single pregnancy at an early age protects women for 30–40 years, and this long-term protection is likely regulated by a relatively stable yet still modifiable method, such as epigenetic reprograming. Long-lasting epigenetic modifications have been shown to be induced by pregnancy and to target the IGF pathway. Understanding how an early first full-term pregnancy protects against breast cancer and the role of epigenetic reprograming of the IGF system may aid in developing new preventative strategies for young healthy women in the future.