• SAN ANTONIO—An investigational gene-based diagnostic assessment for lymph node metastases may improve intraoperative pathology and surgical decision-making, and reduce the need for second axillary node surgeries, according to a large multicenter study presented at the 29th Annual San Antonio Breast Cancer Symposium (abstract 28).

The GeneSearch Breast Lymph Node (BLN) Assay (Veridex, LLC) was found to be 10% to 18% more sensitive than frozen section or touch preparation, the traditional intraoperative methods of detecting metastases, reported Peter W. Blumencranz, MD, medical director of Moffitt Morton Plant Cancer Care, Clearwater, Florida.

The BLN Assay is a rapid closed-tube system using predetermined cut-off points for cytokeratin-19 and mammaglobin that allow it to identify metastases greater than 0.2 mm. It can be performed by a technician with minimal training and thus free up the pathologists' time. It is objective and standardized, providing a "yes or no" response for the presence of metastases, and multiple nodes can be assessed in a single run.

Results of the assay can typically be reported during the operation within 30 to 40 minutes from the time the sentinel node is removed, Dr. Blumencranz said. The test outcomes are intended to be used to guide the decision to excise additional lymph nodes and to aid in staging.

Importantly, he said, the BLN Assay samples 50% of the node, compared with less than 5% with standard approaches. "With permanent section H—E, the actual tissue viewed is only 2% to 5% of the node. This will miss 10% to 15% of clinically relevant metastases," Dr. Blumencranz commented.

Head-to-Head Comparisons

In the study involving 416 patients across 11 clinical sites, fresh sentinel lymph node tissue was tested using the BLN Assay and current methods for lymph node assessment—frozen section (319 samples) or touch preparation cytology (29 samples).