Breast cancer is the second leading cause of cancer-related death among women in the US after lung cancer [1]. In 2009, approximately 40 000 women died from breast cancer and approximately 192 000 new cases were diagnosed in US women [2]. Based on rates from 2004–2006, women have a lifetime risk of developing breast cancer of 12% [3]. Although breast cancer incidence rates have declined in recent years, owing to improvements in early screening and reduction of risk factors, it is important to note that the actual number of Americans who die from the disease is projected to rise in the coming years as the population increases and baby boomers reach the high-risk age for cancer [4].