A study published in the latest issue of JAMA (Journal of the American Medical Association) reports an increase in the incidence of metastatic breast cancer in the group of young women aged 25 through 39.
Rebecca H. Johnson, Franklin L. Chien and Archie Bleyer. Incidence of Breast Cancer With Distant Involvement Among Women in the United States, 1976 to 2009. In JAMA. 2013;309(8):800-805. doi:10.1001/jama.2013.776