Validation Study Using the GeneSearch BLN Assay to Test Sentinel Lymph Nodes From Patients With Breast Cancer

This study will determine the sensitivity, specificity, negative predictive value, and
positive predictive value of the GeneSearch™ BLN Assay in patient samples by comparing its
performance to that of the current methods -- permanent section Hematoxylin and Eosin (H&E)
staining with IHC. Additional marker testing using probes associated with nodal metastases
may be used in the assay performance calculations. The observed performance measures will be
compared to those obtained in the larger U.S. registration trial to show that there are no
differences in the assay's performance.

Inclusion Criteria:

- Previous diagnosis of carcinoma of the breast

- Patient scheduled for sentinel lymph node dissection as per standard of care at the
clinical site

- 18 years or older

- Female or male, and

- Able and willing to give consent to participate in the study

Exclusion Criteria:

- Patients taking part in other research studies that would interfere with their full
participation in this study