Pathwork Diagnostics

Redwood City, CA, July 11, 2011 – Pathwork Diagnostics, Inc., a privately held molecular diagnostics company focused on oncology, announced today a study conducted at the University of California, San Francisco*, demonstrating the high accuracy of its FDA cleared Pathwork® Tissue of Origin Test has been published in the international journal of clinical chemistry Clinica Chimica Acta.

The Tissue of Origin Test aids in the diagnosis of challenging cancer cases such as those that are metastatic or with a complex clinical history and is used by leading clinicians around the country. The Pathwork test is the only FDA-cleared molecular diagnostic test for tissue of origin and has been extensively evaluated in multiple independent studies involving more than 1,100 patient specimens, including large validation studies published in the Journal of Clinical Oncology and the Journal of Molecular Diagnostics.

Cancers are treated differently based on the type of cancer. When the disease is metastatic (spread elsewhere in the body) at the time of diagnosis, determining where the cancer originated can be especially difficult and error-prone. The Tissue of Origin test performs a gene expression profile of the cancerous tissue and provides objective information to assist physicians in making a more definitive diagnosis and choosing the best course of treatment.
In the study, 37 blinded, archived formalin-fixed, paraffin-embedded (FFPE) clinical specimens from the UCSF Department of Pathology, within the 15 tumor tissues on the Pathwork Tissue of Origin Test panel, were tested using the Tissue of Origin Test. In 95% of the cases, the test results were in agreement with the reference diagnosis.
“The Tissue of Origin Test gave a high agreement with the reference diagnosis when archived clinical specimens from UCSF were assessed,” concluded the researchers. “Molecular profiling assays are highly accurate and can be a useful tool in cancer diagnosis.”

The study was published online in Clinica Chimica Acta and will appear in the upcoming July 15 issue. Titled “Gene expression profiling from formalin-fixed, paraffin-embedded tissue for tumor diagnosis,” the study was authored by James P. Grenert, Andrew Smith, Weiming Ruan, Raji Pillai and Alan H.B. Wu.¹

The UCSF study included samples from all 15 tissue types represented on the Pathwork Tissue of Origin Test panel. The tumor specimens, which included high grade/poorly differentiated cases, were selected from FFPE clinical specimens archived from 2000 to 2007 from the UCSF Department of Pathology, under an IRB-approved protocol. The UCSF reference diagnosis was made using clinical history, histological review, immunohistochemistry and imaging studies.

In a previously published blinded, multi-site clinical validation study employing 462 tumor specimens, the Tissue of Origin Test results were in agreement with the available diagnosis in 89% of cases.² The purpose of the UCSF study was to assess, in a second independent study, the overall performance of the test on samples from a laboratory not involved with the clinical validation, in order to confirm that it is consistent with the results of the larger controlled validation study.

The Pathwork Tissue of Origin Test measures the gene expression levels of more than 2,000 genes and compares the gene expression pattern of the patient tumor specimen to that of 15 tissues in the test’s database, to provide information on what type of cancer the patient has. To have a specimen processed by the Pathwork Diagnostics Laboratory using the Tissue of Origin Test or to learn more, call Pathwork Diagnostics at (877) 808-0006 or visit www.pathworkdx.com.

About Pathwork Diagnostics
Pathwork Diagnostics, Inc. is a privately held company based in Redwood City, CA, that develops and commercializes high-value molecular diagnostics for oncology. For more information call toll-free (877) 808-0006 or visit www.pathworkdx.com.

* The information stated above was prepared by Pathwork Diagnostics and reflects solely the opinion of the corporation. Nothing in this statement shall be construed to imply any support or endorsement of Pathwork Diagnostics or any of its products, by The Regents of the University of California, its officers, agents and employees.

1. J.P. Grenert et al, Gene expression profiling from formalin-fixed, paraffin-embedded tissue for tumor diagnosis, Clin Chim Acta. 2011 Jul 15;412(15-16):1462-4. Epub 2011 Apr 7.
2. Pillai et al: Validation and Reproducibility of a Microarray-Based Gene Expression Test for Tumor Identification in FFPE Specimens J Mol Diagn. 2011; 13: 48 - 56.