GeneSearch™ Breast Lymph Node (BLN) Assay Post Approval Study

The primary objective of this clinical study is to gather data to estimate the positive
predictive concordance (PPC) between the GeneSearch™ BLN Assay and histology as routinely
practiced, i.e., routine H&E histology of sentinel lymph node(s) (SLN) and, when available,
routine histology of non-sentinel axillary lymph nodes (ALN). This study will provide
information on the assay that will augment the performance data gained in pre-market
validation studies. In addition, with the assay being used for ALND decision-making, the
metastatic status of the non-sentinel axillary nodes can be taken into account in the
performance measures, i.e., if the patient's sentinel or non-sentinel nodes are
histologically positive, the patient will be considered positive for the primary comparison
to the assay results.

Inclusion Criteria:

- Pre-operatively established diagnosis of invasive carcinoma of the breast

- Scheduled for axillary sentinel lymph node dissection as per standard of care at the
clinical site for newly diagnosed breast cancer patients

- Patients for whom the GeneSearch™ BLN Assay will be used intra-operatively to make a
decision for an axillary lymph node dissection

- 18 years of age or older

- Female or male

- Willing and able to give informed consent to participate in the study

Exclusion Criteria:

- Previous diagnosis of lymphoma

- Subjects participating in other research studies that would interfere with their full
participation in this study

- Patients and/or conditions with 'interfering substances' as listed in the IFU.

- Patients who have had any pre-operative treatment for breast cancer including
neoadjuvant and/or hormonal intervention such as aromatase inhibitors or tamoxifen