Diagnosis of uncertain primary tumors with the Pathwork^® tissue-of-origin test

Abstract

Clinical workup of metastatic malignancies of unknown origin is an arduous and expensive process, which is reported to be unsuccessful in up to 30% of cases. Global gene expression-based molecular testing may offer accurate classification of metastatic tumors in which a primary site has not been identified. Recently, the US FDA cleared the Pathwork^® tissue-of-origin test, which is a gene expression microarray-based test that quantifies the molecular similarity of tumor specimens to 15 known tissue types. A blinded, multicenter validation on poorly differentiated and undifferentiated tumors showed 87.8% sensitivity and 99.4% specificity in frozen tissue samples. The availability of ancillary gene expression-based molecular tests for tissue of origin determination represents a milestone in cancer patient management as part of the personalized medicine revolution.

Keywords::

• gene expression analysis
• gene expression classifier
• molecular testing
• tissue of origin
• uncertain primary cancer

Financial & competing interests disclosure

Federico A Monzon and Catherine I Dumur have received funding from Pathwork Diagnostics for the performance of the reproducibility and clinical validations studies of the tissue of origin test. Federico A Monzon has received honoraria for speaking engagements discussing the results of these studies and for consultation regarding development of tests unrelated to the tissue of origin test. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.