The Oncoype DX test is used to determine a patient’s risk of breast cancer recurrence. It is often used to guide breast cancer treatment. For example, some women may benefit from chemotherapy, while others may not need it and can be spared from its side effects. The results of Oncotype DX may be used to help make this decision.
In this study, researchers are comparing the use of hormone therapy with and without chemotherapy in women whose breast cancers contain hormone receptors and are HER2-negative (making them ineligible for trastuzumab treatment), who also had one to three underarm lymph nodes containing cancer cells and whose Oncotype DX recurrence scores are 25 or less. Survival between the women who receive chemotherapy and those do not will be compared.
The researchers will see if the survival difference between the two groups corresponds to an Oncotype DX recurrence score which may serve as a cut-off point to determine whether or not a woman stands to benefit from chemotherapy. It is currently not know what this cut-off point may be among patients with recurrence scores of 25 or less.