OT1-03-01: A Randomized Phase III Clinical Trial of Standard Adjuvant Endocrine Therapy +/− Chemotherapy in Patients (pts) with 1–3 Positive Nodes, Hormone Receptor (HR)-Positive and HER2−Negative Breast Cancer with Recurrence Score (RS) of 25 or Less: SWOG S1007.

Abstract

Abstract Background Multi-gene tumor assays have provided clinically useful prognostic information for pts with HR receptor and node-positive breast cancer. The 21-gene RS was shown to be prognostic for pts treated with tamoxifen alone, and exploratory studies suggested that it may be predictive of benefit from chemotherapy. In retrospective analyses from SWOG S8814, pts with low RS appeared to get no benefit from adjuvant CAF chemotherapy, while those with higher RS did. These retrospective data require validation, especially since more modern chemotherapy might be more effective than the regimen used in S8814. Specific Aims/Trial Design: In January 2011, SWOG activated a phase III randomized clinical trial (registration number NCT01272037) to test the efficacy of using modern chemotherapy regimens in node positive pts with low RS, whose prognosis is still moderately poor but may not benefit from adjuvant chemotherapy based on tumor biology predicted by the RS value. The trial is similar to the Tailor RX study, but focuses on a node-positive population with low and intermediate RS. Eligibility Criteria: Pts with 1 to 3 positive lymph nodes, HR-positive and HER2−negative invasive breast cancer with RS ≤ 25 are eligible for randomization. Pts will be informed of their RS. Target and Present Accrual: Approximately 9400 patients will be screened to randomize 4000, stratified by RS (0-13 vs. 14–25), menopausal status, and axillary surgery (sentinel node vs. complete dissection); 46 are presently registered. Statistical Methods: The trial is powered to find a significant interaction of treatment assignment and the continuous RS value and, subsequently, derive a cut point for using the assay to guide treatment decisions. Pts who consent to screening are required to consent to banking of the tumor tissue and blood for further studies. Patient Reported Outcomes will be collected pre, post-screening and post-randomization. The study also has a cost-effectiveness analysis. Funding: Supported in part by National Cancer Institute grants CA32102 & CA38926, and in part by the Susan G. Komen for the Cure® Research Program, and the Breast Cancer Research Foundation. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT1-03-01.