One of the most surprising aspects of the study is the lack of difference in breast cancer mortality rates between the different surgical groups. Whether a woman chose a lumpectomy, which is often followed by radiation therapy, unilateral mastectomy, or bilateral mastectomy, her chances of dying from breast cancer were nearly identical over the 20-year follow-up period. Specifically, the breast cancer mortality rates were 8.54% for those who underwent a lumpectomy, 9.07% for those who had a unilateral mastectomy, and 8.50% for those who chose a bilateral mastectomy.