23 advanced breast cancer includes both metastatic breast cancer and locally advanced breast cancer (stage III) and locally recurrent breast cancer Akt a serine/threonine-specific protein kinase BRCA mutation mutation in the tumor-suppressor gene BRCA1 or BRCA2, associated with hereditary breast cancer CSO Common Scientific Outline (www.icrpartnership.org/CSO.cfm) de novo MBC breast cancer that is metastatic at the time of first diagnosis ER– estrogen receptor negative/hormone insensitive breast cancer ER+ estrogen receptor positive/hormone sensitive breast cancer ErbB epidermal growth factor receptor (protein family) gHRAsp Grants in the Health Research Alliance Shared Portfolio (www.ghrasp.org), HCPs HCPs HER2 human epidermal growth factor receptor 2 hormone-sensitive MBC MBC where tumor growth is promoted by estrogen and/or progesterone HRA Health Research Alliance ICRP International Cancer Research Partnership incidence Rate of occurrence of new cases in the population (measure risk of developing a disease) IOM Institute of Medicine KOL key opinion leader MBC metastatic breast cancer MBC Alliance Metastatic Breast Cancer Alliance (also called the Alliance) mTOR mechanistic target of rapamycin (serine/threonine protein kinase) NCI National Cancer Institute PDQ Physician Data Query PI3K phosphatidylinositide 3-kinase prevalence proportion of cases in the population (measures how widespread the disease is) RECIST Response Evaluation Criteria in Solid Tumors SEER Surveillance, Epidemiology, and End Results program of the National Cancer Institute (NCI) stage IV breast cancer another term for metastatic breast cancer TBCRC Translational Breast Cancer Research Consortium TN MBC triple-negative (hormone insensitive and HER2-negative) metastatic breast cancer TNBC triple-negative (hormone insensitive) breast cancer US United States