Molecular Residual Disease Assessment in a Representative Diverse Population of Patients With Early-stage Breast Cancer

The purpose of this study is to determine how circulating tumor DNA (ctDNA), a sign of minimal residual disease (MRD), is detectable after surgery in patients with early HR+/HER2- breast cancer that has spread to 1-3 lymph nodes. Researchers aim to understand if ctDNA detection can identify patients at higher risk of recurrence and guide better treatment decisions. A key aspect is the inclusion of a dedicated cohort of African American/Black women, a group underrepresented in molecular residual disease (MRD) research despite experiencing more aggressive breast cancers. This study will correlate ctDNA results with treatment patterns (radiotherapy, systemic therapy) and outcomes (recurrence-free and overall survival) in both non-African American and African American participants.

In order to participate in this study, a subject must meet all of the eligibility criteria outlined below. Inclusion Criteria: 1. Written informed consent obtained to participate in the study and HIPAA authorization for release of personal health information. 2. Subjects are willing and able to comply with study procedures based on the judgment of the investigator. 3. Age ≥ 18 years at time of consent. 4. Subject must have had surgical intervention and must have sufficient archival specimens from either the primary tumor or a lymph node for ctDNA assay development, as specified in the lab manual. Exclusion Criteria: 1. Subjects must not have had prior neoadjuvant therapy. 2. Evidence of metastatic disease in imaging. 3. N1 mic or isolated tumor cells in the lymph nodes