1 23 Breast Cancer Research and Treatment ISSN 0167-6806 Breast Cancer Res Treat DOI 10.1007/s10549-013-2583-1 Contralateral mastectomy improves survival in women with BRCA1/2- associated breast cancer D. Gareth R. Evans, Sarah L. Ingham, Andrew Baildam, Gary L. Ross, Fiona Lalloo, Iain Buchan & Anthony Howell