Clinical Evaluation of OSNA Breast Cancer System to Test Sentinel Lymph Nodes From Patients With Breast Cancer

Inclusion Criteria: * Male or Female patients, over the age of 18, diagnosed pre-surgically with T1 or T2 breast cancer and scheduled for surgery including sentinel node dissection. * Patients who have read and understand the informed consent form and are capable and willing to provide written informed consent. Exclusion Criteria: * Patients diagnosed pre-surgically with large or locally advanced (T3 and T4) breast cancers. * Patients diagnosed with inflammatory breast cancer. * Patients diagnosed with ductal carcinoma in situ (DCIS) when breast conserving is to be done. * Patients who are pregnant, as confirmed by a patient/treating physician interview. * Patients with suspicious palpable axillary lymph nodes. * Patients currently being treated for or previously diagnosed with, another type of carcinoma. * Patients who have undergone prior non-oncologic breast surgery or axillary surgery. * Patients who have received pre-operative systemic therapy. * Patients who are incapable of providing written informed consent. * Patients who have been judged to be inappropriate by a medical care provider (i.e. surgeon, oncologist, pathologists, etc.).