The Pathwork Tissue of Origin Test, available through the Pathwork Diagnostics Laboratory, is the FDA-cleared molecular diagnostic test for tissue of origin.

The test study assesses its clinical utility and real-world effect on diagnosis and patient management and collected data from 66 participating physicians who have ordered the Pathwork Tissue of Origin Test for 111 patients with difficult-to-diagnose primary cancers.

The study results indicated that most patients had undergone extensive evaluation including multiple imaging tests and average of 10 immunohistochemistry tests prior to gene expression analysis.

The Tissue of Origin Test, requiring less amounts of formaldehyde fixed-paraffin embedded (FFPE) tumor tissue, measures the gene expression levels in more than 2,000 genes and compares the gene expression pattern of the specimen to that of 15 tissues in the test database, to indicate the most likely match.