Data Presented at Cancer Molecular Markers Meeting Suggests Clinical Benefit for Integrating New Molec...( SUNNYVALE Calif. Oct. 31 /- Pathw...)

SUNNYVALE, Calif., Oct. 31 /PRNewswire/ -- Pathwork Diagnostics, a molecular diagnostics company focused on oncology, and City of Hope Hospital presented today the results from a meta-analysis examining the use of immunohistochemistry (IHC) to determine the origin of metastatic cancer at the second annual ASCO-NCI-EORTC Meeting on Molecular Markers in Cancer in Hollywood, Fla. In the meta-analysis, published peer-reviewed studies of the accuracy of IHC were reviewed. Researchers from Pathwork Diagnostics and the City of Hope Hospital, a leading cancer research and treatment center, found that various panels of IHC stains alone can perform poorly when attempting to determine the tissue of origin for metastatic tumors.

In the poster presentation, entitled "A Meta-Analysis of the Use of IHC Testing in Metastatic Disease: The Need for Integration of New Technologies," Dr. Larry Weiss, Chair, Division of Pathology, City of Hope, highlighted the results from the meta-analysis of five IHC studies published between 1993 and 2007 that quantified IHC performance in tissue identification. The results found that the blinded use of IHC panels identified the correct tissue of origin in only 66 percent of metastatic tumors, and 82 percent of the tumors in studies containing a blend of primary and metastatic tumors.

"Pathologists utilize IHC stains frequently to determine the origin of metastatic tumors; however, objective evidence as to its effectiveness has not been convincingly presented and these results confirm that there is a pressing clinical need for improved diagnostic methods," said Dr. Weiss. "The results also establish minimum performance requirements for any new diagnostic test intended to aid the pathologist and oncologist in tissue of origin determination as well as underscore the importance of well-designed validation studies that are statistically sound, adequately sized, and appropriately masked. It is only through such validation that new
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