On Dec. 7, 2005, results from several studies presented at the San Antonio Breast Cancer Symposium validated that a new test can predict the risk of breast cancer recurrence in a sizable group of patients. The studies also appeared to identify which of those patients might benefit most from chemotherapy. The studies were heralded by researchers as an important moment in the move toward individualized cancer care. Central to the investigations was a test, Oncotype DX, that analyzed the expression of a 21-gene panel in biopsy samples from women with estrogen-dependent, lymph-node negative breast cancer, which accounts for more than 50,000 breast cancer cases in the United States each year.