(SWOG S1007) A Phase III, Randomized Clinical Trial of Standard Adjuvant Endocrine Therapy +/- Chemotherapy in Patients with 1-3 positive Nodes, Hormone Receptor-Positive and HER2-Negative Breast Cancer with Recurrence Sco...

Summary The purpose of this study is to find out if the Onotype DX Recurrence Score can help decide whether patients should receive chemotherapy or not.  This study is being done in patients with lower Recurrence Scores (25 or less).  Currently most women who have breast cancer are treated with endocrine therapy (treatment that works with hormones).  Many women also received chemotherapy.  No one really knows which patients with lower Recurrence Scores need to get chemotherapy.  Some women may be getting chemotherapy who do not need it.  These women may be exposed to the side-effects of their treatment that are not  a necessary risk in relation to the benefit they receive.  If the results of the study show that the benefit for getting chemotherapy is dependant on the Recurrence Score, the study should be able to identify a Recurrence Score level where chemotherapy should be considered (and a recurrence score level where chemotherapy may not be needed).