Pathwork Tissue of Origin Test Validation Study Published in Journal of Clinica...( Largest Study on a Test that Identifi...),Health

Largest Study on a Test that Identifies Tumors with Uncertain Origins Demonstrates Unmatched Performance

REDWOOD CITY, Calif., March 30 /PRNewswire/ -- Pathwork Diagnostics, Inc., a molecular diagnostics company focused on oncology, announced today that the Journal of Clinical Oncology (JCO) has published the results of the Pathwork(R) Tissue of Origin Test validation study in a paper entitled, "Multicenter Validation of a 1,550-Gene Expression Profile for Identification of Tumor Tissue of Origin." The results of the 547-specimen study showed that the test has significant potential to reduce diagnostic uncertainty for poorly differentiated, undifferentiated or metastatic tumors. To date, no other tests in this category have undergone as large a clinical validation study or produced such strong results.

"This study, which is the first of many clinical studies being performed, clearly demonstrates the exceptional performance and robust science underlying our test," said Deborah J. Neff, President and Chief Executive Officer of Pathwork Diagnostics. "We believe the Tissue of Origin Test can benefit physicians by allowing them to diagnose tumors with uncertain origins with greater confidence because the test provides objective data and the ability to both rule in and rule out tumor types."

To determine the tumor's origin, the Pathwork Tissue of Origin Test uses microarray technology to measure the gene expression pattern, comprising more than 1,500 genes, in a tumor with an uncertain origin and compare it to expression patterns of a panel of 15 known tumor types, representing 90 percent of all solid tumors and 58 morphologies overall. In the multicenter, blinded clinical validation study, which was used as the basis for the test's FDA clearance in July 2008, the test examined 547 frozen tumor specimens from patients diagnosed with one of the tumor types in the panel, all of which were either metasta
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