Pathologically (histologically or cytologically) proven diagnosis of invasive breast cancer Patients must have histologically confirmed ER+ and/or PR+, HER2-, early invasive breast cancer. Participants must have histologically confirmed invasive breast cancer; all histologic subtypes are eligible Histologically confirmed HER2-negative localized breast cancer by core biopsy. Participants must have histologically or cytologically confirmed invasive breast cancer Histologically confirmed invasive cancer of the breast Subjects with histologically confirmed metastatic or unresectable breast cancer Histologically confirmed diagnosis of invasive breast cancer Histologically proven invasive adenocarcinoma of breast Histologically-confirmed, primary, invasive breast cancer diagnosed within 5 years of study entry Subjects with histologically confirmed metastatic breast cancer that is either TNBC or HR-positive Patients with histologically confirmed intact primary cancer that is confirmed invasive carcinoma of the breast, with at least 1.0 cm residual disease as measured by mammography, ultrasound, or breast magnetic resonance imaging (MRI) after neoadjuvant anthracycline based chemotherapy Subjects have histologically confirmed adenocarcinoma of the breast - all breast cancer subtypes are allowed Histologically confirmed breast cancer Newly diagnosed histologically or cytologically confirmed operable invasive breast cancer defined as cT1 or T2, N0-1, and M0 Histologically confirmed diagnosis of invasive breast cancer Histologically confirmed diagnosis of invasive breast cancer Newly diagnosed histologically confirmed invasive breast cancer Histologically confirmed HER2-positive metastatic breast cancer Histologically confirmed diagnosis of invasive or non-invasive breast cancer Histologically confirmed invasive primary breast cancer Participants must have histologically confirmed invasive breast cancer; all histologic subtypes are eligible Histologically confirmed invasive breast cancer Female with histologically confirmed breast cancer Histologically confirmed unilateral primary invasive adenocarcinoma of the breast Histologically or cytologically confirmed metastatic breast cancer Histologically confirmed invasive breast cancer with a primary tumor size of greater than (>) 2 cm Patients must have histologically confirmed invasive breast cancer with a primary tumor >= 2 cm in greatest dimension as measured by clinical or radiologic examination Postmenopausal women with histologically or cytologically confirmed invasive, ER+/HER- (defined by local guidelines) metastatic or inoperable, locally advance breast cancer History of histologically-confirmed bilateral breast cancer Histologically or cytologically confirmed invasive breast cancer with distant metastasis PHASE II: Participants must have histologically confirmed invasive breast cancer; all histologic subtypes are eligible Histologically or cytologically confirmed breast cancer with evidence of metastatic disease. Participants must have histologically confirmed HER2+ (3+ by immunohistochemistry and/or FISH ratio >= 2.0) invasive breast cancer; central confirmation of HER2 status is not required Histologically confirmed invasive cancer of the breast. Participants must have histologically confirmed invasive breast cancer; all histologic subtypes are eligible Histologically confirmed Stage I to III invasive breast cancer. Subjects may have more than one synchronous primary breast tumor. Patients must have histologically or cytologically confirmed invasive cancer of the breast Histologically confirmed primary invasive adenocarcinoma of the breast Pathologically confirmed invasive cancer of the breast Histologically or cytologically documented breast cancer Histologically or cytologically confirmed HER2-positive invasive breast cancer, with Stage IV disease; Histologically confirmed unilateral primary invasive adenocarcinoma of the breast Patients with histologically confirmed invasive breast cancer, stage I - IV, treated at Lyndon B. Johnson General Hospital in the Harris Health System Prior history of histologically confirmed bilateral invasive breast cancer Histologically or cytologically confirmed breast cancer A history of histologically-confirmed bilateral invasive breast cancer Histologically confirmed metastatic breast cancer Diagnosed with histologically-proven invasive breast cancer Histologically confirmed cT0-4, N1 breast cancer Group I: Diagnosis of histologically confirmed invasive breast cancer Group II: Diagnosis of histologically confirmed invasive breast cancer Women with histologically proven invasive breast cancer and no distant metastases and; Patients must have histologically confirmed invasive breast cancer Histologically or cytologically confirmed primary breast cancer.