Inclusion Criteria:  250 subjects must meet all of these inclusion criteria:  Capable of providing informed consent 140 subjects must meet all of these inclusion criteria: Women (≥18 years of age) diagnosed with primary breast cancer (any subtype ER/PR+ and/or HER2+, ER-/PR-/HER2-) at least 6 months before patient presented with suspected metastases Prior diagnosis (at least 6 months ago- not de novo metastasis presentation) and treatment for primary breast cancer Patients presenting with symptoms of first recurrence of breast cancer and metastasis from a mix of bone, lung, liver, and/or brain sites No history of any other cancers; no known other dysplasia or in-situ prior diagnosis The suspected metastases must be outside the ipsilateral breast, axilla infra/supraclavicular areas. In those with suspected metastases in contralateral axilla, infra/supraclavicular areas only a new contralateral breast primary must be excluded by physical exam, mammogram or MRI  Ability to access 6-month outcome data. (De-identified, consented patients included for 2nd draw at 6-month timepoint) [ 30 subjects' blood samples will from cases where patient refuses biopsy or tissue biopsy procedure is challenging or unsafe will have primary diagnosis data and imaging results. No matched tissue biopsies at recurrence will be included for those samples.]  200 Subjects must meet all of these inclusion criteria:  Patients must have suspected recurrent metastatic breast cancer (BCa) that will be confirmed by tissue biopsy that is expected to yield tissue adequate for histologic examination Data from primary BCa diagnosis must be included in pathology report or data entry. Detailed pathology report included for all samples with recurrence tissue biopsy Detailed description with stains, morphology as to how malignancy/cancer of origin was determined.  Total subtypes: HER2+ cases; HR+ cases; HER2-HR- cases  50 Subjects of confirmed cancer of origin other than breast or non-malignant condition (lung, colon, ovarian cancer; other).  Exclusion Criteria:  Tissue biopsy occurs prior to blood collection for CTCs and ctDNA New treatment for suspected metastases commences prior to blood collection for CTCs and ctDNA Patient has received previous lines of systemic treatment for metastatic BC Previous history of an invasive non-BC apart from cancers treated with curative intent at least 5 years previously with no recurrence since diagnosis, with the exception of a non-melanoma skin cancer Subjects unable to provide informed consent Subjects undergoing only cytologic evaluation of suspected metastases