Evaluating the Addition of Adjuvant Chemotherapy to Ovarian Function Suppression Plus Endocrine Therapy in Premenopausal Patients With pN0-1, ER-Positive/HER2-Negative Breast Cancer and an Oncotype Recurrence Score Less Than or Equal to 25

This Phase III clinical trial studies whether adding chemotherapy to standard hormone treatment helps prevent cancer from returning in premenopausal women with early-stage breast cancer. Participants are typically divided into two groups: one receives hormone therapy alone, while the other receives chemotherapy followed by hormone therapy. The hormone treatment involves an aromatase inhibitor combined with medication to suppress ovarian function for five years. These treatments work by lowering estrogen levels or blocking estrogen’s ability to help cancer cells grow.

You may be eligible if you are a premenopausal woman with ER-positive, HER2-negative breast cancer that has been surgically removed. The study focuses on patients with specific "Oncotype DX" recurrence scores: generally 16–25 if the cancer has not spread to the lymph nodes, or 0–25 if it has spread to 1–3 nodes. You must be within 16 weeks of your last breast surgery and have generally good heart, kidney, and liver health. You cannot join if the cancer has spread to distant parts of the body or if you have already started chemotherapy for this diagnosis.

Participation involves regular clinic visits for infusions or injections, depending on your treatment group. Before enrolling, discuss with your doctor how chemotherapy might impact your long-term health and whether your specific genomic test results make this study a good fit for you.