Abbeville

Researchers are studying premenopausal women with early-stage breast cancer that is estrogen receptor-positive and HER2-negative, focusing on tumors with specific gene recurrence scores. The trial aims to find out if adding chemotherapy to ovarian function suppression plus endocrine therapy improves invasive breast cancer-free survival compared to ovarian function suppression plus endocrine therapy alone. This Phase III trial addresses the need for better treatments in younger women, given their higher risk and past conflicting study results on ovarian suppression and chemotherapy. Participants are randomly assigned to one of two groups one receiving ovarian function suppression combined with an aromatase inhibitor for five years, and the other receiving adjuvant chemotherapy followed by the same ovarian function suppression and aromatase inhibitor regimen. Choices for the aromatase inhibitor and gonadotropin releasing hormone agonist are made by the investigator, with options including drugs such as goserelin, leuprolide, or triptorelin. Endocrine treatment beyond five years is at the investigators discretion, and bilateral oophorectomy may be used instead of ovarian suppression if preferred. During the study, participants are monitored over 11 years from randomization, with measurements including invasive breast cancer-free survival as the primary outcome. Secondary outcomes include disease-free survival, overall survival, recurrence intervals, menopausal symptoms, and pain during aromatase inhibitor therapy. Safety and treatment effects are assessed through regular evaluations, and participants continue to be followed long term to understand the impact of treatments on their breast cancer outcomes.