The number corresponds with the specific likelihood of breast cancer recurrence within 10 years of the initial diagnosis and is classified by low, intermediate, or high risk. The RS categorizes hormone receptor-positive www.selleckchem.com/products/CHIR-258.html lymph node-negative disease into low (RS < 18), intermediate (RS 18�C31) or high (RS > 31) risk groups. In 2004, Paik and colleagues12 reported distant recurrence rates of 6.8%, 14.3%, and 30.5% in the different risk groups, respectively. The RS assay may also predict the magnitude of chemotherapy benefit.54,55 Unlike the MammaPrint assay, Oncotype DX does not require freshly prepared tissues. In collaboration with several independent investigators, the test has been evaluated in numerous studies involving over 3300 patients.
The Southwest Oncology Group 8814 analysis, for instance, demonstrated both prognostic and predictive significance of Oncotype DX in women with ER-positive early breast cancer and positive lymph nodes.56 The NSABP B-14 and B-20 studies clinically validated a major role of Oncotype DX in recurrence risk estimation and also demonstrated a possible prediction of the magnitude of chemotherapy benefit.57 Generally, patients with a high RS showed greater benefit from additional chemotherapy than patients with a low RS.47 Chemotherapy seems to provide little, if any, benefit for patients with low RS, despite the presence of a low number of positive nodes.54 Another large clinical study conducted by Kaiser Permanente confirmed in a community setting that Oncotype DX helps to predict the likelihood of breast cancer survival at 10 years among ER-positive tamoxifen-treated and systemically untreated patients.
58 According to the National Comprehensive Cancer Network Guidelines, Oncotype DX should be considered as an option for patients with node-negative, hormone receptor-positive, HER2-negative tumors 0.6 to 1 cm in size that are moderately to poorly differentiated, or those with angiolymphatic invasion, high nuclear or histologic grade, and tumors > 1 cm in size.59 To assess the important question regarding how to manage the large population of patients at intermediate risk (RS between 11�C25), the Trial Assigning Individualized Options for Treatment (Rx) (TAILORx)60 was launched in May, 2006. In this prospective trial enrolling over 10,000 patients, Oncotype DX is currently being evaluated in nodenegative, ER-positive breast cancer.
It remains to be seen whether trial Carfilzomib results will be presented in 2014, as expected. Results of the TAILORx trial will provide important information on how to manage the large population of intermediate risk patients. The translational arm of the ATAC study (TransATAC)61 assessed biomarkers for their prediction of overall and distant recurrence in the translational arm of the ATAC study. The authors found out that each of the factors, ER, progesterone receptor, HER2, and Ki67, was associated with the risk of recurrence.