The American Cancer Society has updated the guidelines for breast cancer screening. Under the new guidelines, breast cancer screening can be started at age 45 instead of 40 (http://www.cancer.org/cancer/news/news/american-cancer-society-releases-new-breast-cancer-guidelines). At the same time, organizations such as Mayo Clinic and Breastcancer.org stand by their recommendation that all women have mammograms annually starting at age 40. (http://www.breastcancer.org/research-news/acs-guidelines-recommend-mammograms-at-45). Nancy L. Keating stated in an editorial in JAMA (http://jama.jamanetwork.com/article.aspx?articleid=2463237) that the debate is far from settled elsewhere in the world.