For patients with breast cancer, it's important to find any remaining cancer cells after they've had their main treatment. Even a few cells, called minimal residual disease (MRD), can lead to the cancer coming back later.

A way to find these cells is by looking for tiny bits of cancer DNA that are shed into the blood. This is called circulating tumor DNA (ctDNA). A simple blood test, often called a liquid biopsy, can detect this ctDNA. This research aims to see if finding this cancer DNA in the blood can help predict if a patient's cancer will return. It also may help find out if the treatment is working.

Ultimately, the results of this research may help doctors better manage breast cancer and develop new and improved tests and treatments.

Inclusion Criteria:

All Cohorts:

1. Willing and able to participate in the research and provide biospecimens
2. Willing and able to provide informed consent
3. Must be diagnosed with breast cancer

Cohort 1: Neoadjuvant Treatment Cohort 1A: Newly Diagnosed, High Risk HR+,HER2-

1. A known or suspected HR+, HER2- breast cancer treated with curative intent (Stage II to III disease)
2. Patients are considered at high risk of recurrence, defined as 4 or more positive axillary lymph nodes (ALNs), or between 1-3 positive ALNs and either grade 3 disease or tumor size of 5 cm or larger.

Cohort 1B: HER2+ 1. A known or suspected HER2+ breast cancer treated with curative intent (Stage II to III disease). Inclusive of HR+ or HR- patients.

Cohort 1C: Triple Negative Breast Cancer

1. A known or suspected triple negative breast cancer treated with curative intent (Stage I to III disease).

Cohort 2: Adjuvant Therapy / Surveillance Cohort 2A: Newly Diagnosed HR+,HER2-

1. A known or suspected HR+, HER2- breast cancer treated with curative intent (Stage II to III disease)
2. Patients are considered at high risk of recurrence, defined as 4 or more positive axillary lymph nodes (ALNs), or between 1-3 positive ALNs and either grade 3 disease or tumor size of 5 cm or larger.
3. Have undergone curative intent surgery with no clinical evidence of disease.

Cohort 2B: HER2+

1. A known or suspected HER2+ breast cancer treated with curative intent (Stage II to III disease)
2. Have undergone curative intent surgery with no clinical evidence of disease.

Cohort 2C: Triple Negative Breast Cancer

1. A known or suspected triple negative breast cancer treated with curative intent (Stage I to III disease)
2. Have undergone curative intent surgery with no clinical evidence of disease.

Cohort 3: 5-Years Post-Diagnosis Surveillance (NED)

1. A known HR+, HER2- breast cancer treated with curative intent (Stage II to III disease).
2. No Evidence of Disease (NED) ≥ 5 years from initial diagnosis.
3. Patients are considered at high risk of recurrence, defined as 4 or more positive axillary lymph nodes (ALNs), or between 1-3 positive ALNs and either grade 3 disease or tumor size of 5 cm or larger.

Exclusion Criteria:

1. Not willing or able to adhere with the study procedures
2. Active secondary malignancy
3. Diagnosis of a malignancy within 3 years of breast cancer diagnosis Note: Ductal carcinoma in situ (DCIS, ipsilateral or contralateral) within 3 years is not excluded.

The population of this study includes early stage breast cancer patients with triple negative breast cancer (Stages I to III), HER2 positive (Stages II and III), and high risk HR positive HER-2 negative (Stages II and III).