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.

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.