Circulating Tumor DNA Based Minimal Residual Disease Detection for Patients With Early-Stage Breast Cancer

This clinical trial studies how well circulating tumor deoxyribonucleic acid (ctDNA) based minimal residual disease (MRD) detection works for patients with early-stage breast cancer. MRD refers to a very small number of tumor cells that remain in the body during or after treatment. ctDNA refers to small pieces of DNA that are released into a person's blood by tumor cells as they die. Management of patients after cancer surgery remains a clinical dilemma, particularly for cancer detected at earlier stages as many patients are cured by surgery alone. This results in very large clinical trials required to demonstrate a modest benefit from treatment. Using ctDNA MRD testing in early-stage breast cancer patients receiving standard treatment may help researchers identify groups that would benefit from additional therapy, leading to better outcomes.

Inclusion Criteria: * Documented written informed consent of the participant * Age ≥ 18 years * Diagnosis of stage I-III breast cancer (any gender) * Malignancy must be epithelial. Non-epithelial breast malignancies such as lymphoma or sarcoma are not allowed * Willingness to: * Provide blood samples * Provide archival tumor tissue sample (only necessary for Cohort 2 if analysis of surgical tissue was not successful) * Provide tumor tissue sample from resection/surgery (only necessary for Cohort 1 if analysis of surgical tissue was not successful) * Permit medical record review * Fall into one of the following categories defined below: Cohort 1, Subgroup A or B OR Cohort 2 * COHORT 1: Must have archival diagnostic tissue available * COHORT 1: Scheduled to undergo, but has not yet begun, neoadjuvant systemic therapy followed by curative resection * COHORT 1 (Subgroup A): HER2+ by current American Society of Clinical Oncology (ASCO)/College of American Pathologist (CAP) guidelines (any ER/PR status) * COHORT 1 (Subgroup B): Triple negative (ER, PR and HER2 negative). Defined as ER and PR ≤ 10% by immunohistochemistry (IHC) and HER2 negative, by current ASCO/CAP guidelines * COHORT 2: Scheduled to undergo upfront curative surgical resection with or without adjuvant chemotherapy followed by adjuvant endocrine therapy * COHORT 2: ER+/any PR/HER2- (ER positive defined as ER \> 10% by IHC) Exclusion Criteria: * Ductal carcinoma in situ * Inability to safely provide sequential blood samples * Prior or concurrent invasive malignancy (unless disease free \> 5 years) * An employee who is under the direct/ indirect supervision of the principal investigator (PI)/ a co-investigator/ the study manager * A direct study team member * Inability to give informed consent