CHICAGO – The largest breast cancer adjuvant study ever performed, the Trial Assigning IndividuaLized Options for Treatment (Rx), or TAILORx, showed conclusively that the Oncotype DX Breast Recurrence Score (RS) test identified 70 percent of early stage breast cancer patients who receive no benefit from chemotherapy and can be treated effectively with endocrine therapy (ET) alone. Findings also showed that chemotherapy may provide life-saving benefit to the other 30 percent of such patients.