Gene expression profiling from formalin-fixed, paraffin-embedded tissue for tumor diagnosis

Area of Science:

• Oncology
• Molecular Diagnostics
• Pathology

Background:

• Molecular profiling assays are advancing tumor diagnosis.
• Formalin-fixed, paraffin-embedded (FFPE) tissues are now viable for microarray-based assays.
• The Pathwork Tissue of Origin (TOO) Test utilizes FFPE tissue for tumor diagnosis.

Purpose of the Study:

• To evaluate the performance of the TOO Test.
• To assess the TOO Test on routine specimens from an independent laboratory.

Main Methods:

• Tested 45 blinded, archived clinical specimens.
• Processed total RNA for cDNA labeling and hybridization to Pathchip microarrays.
• Analyzed hybridization data using a 2000-gene classification model.

Main Results:

• 98% of specimens (44/45) were successfully processed.
• 35 out of 37 (95%) cases showed agreement with the reference diagnosis.
• The reference diagnosis was not ruled out in any case.

Conclusions:

• The TOO Test demonstrated high agreement with reference diagnoses for archived FFPE specimens.
• Molecular profiling assays, like the TOO Test, are highly accurate.
• These assays serve as a valuable tool in cancer diagnosis.