Pathwork Diagnostics laboratory service

Comprehensive service, from sample preparation to analysis and reporting

The FDA-cleared Pathwork Tissue of Origin Test is available through the Pathwork Diagnostics laboratory in Redwood City, California. The test delivers a new level of confidence in the diagnosis of challenging tumors, including metastatic, poorly differentiated, and undifferentiated tumors.

Clinical validation:

• In 462 formalin-fixed, paraffin-embedded (FFPE) specimens, the test demonstrated 89% positive percent agreement (akin to sensitivity) with available diagnoses, and greater than 99% negative percent agreement (akin to specificity) in specimens that had previously been identified with existing methods as being among the 15 tumor types on the panel.¹

The Pathwork Diagnostics laboratory provides a comprehensive service for the preparation and analysis of samples. Proprietary analytics are used to interpret the data, and a report is generated that provides clear, objective information on the Similarity Score for each tumor type.

When to order the Tissue of Origin Test:

When there is clinical uncertainty about a challenging tumor, the Tissue of Origin Test can help fill the information gap with accurate, objective information. The physician should consider ordering the test as a diagnostic aid when:

• The cancer is found in an unexpected location.
• The cancer is found in multiple locations, indicating metastatic disease.
• The tumor cells are poorly differentiated or undifferentiated, making them difficult to interpret.

How results are reported:

The Pathwork laboratory will process the specimen, run the Tissue of Origin Test, and report the results to the ordering physician.

• An objective Similarity Score for each of 15 potential tissue types will be generated.
• An interpretation of the results will rule in or rule out specific tumor types.

This easy-to-interpret report provides clear, objective information with a Similarity Score for each tumor type; this information can help physicians in their goal to make better treatment decisions.

View Sample Pathwork Tissue of Origin Report

NOTE: Tumor types not in the Pathwork Tissue of Origin Test database may have RNA expression patterns that are similar to patterns in the database. Therefore, results cannot be used to distinguish tumor types in the database from tumor types not in the database.

How to order the test:

Request a Specimen Collection and Shipping Kit that includes instructions and materials for sample collection and shipping. Learn more about ordering the Tissue of Origin Test, or call toll-free 1.877.808.0006.

Specimen requirements:

Pathwork Diagnostics prefers a block of FFPE tissue containing at least 1 mm² of TUMOR tissue by area.  Include an H&E slide if possible.

If an FFPE block is not available, send unstained slides (USS) of at least 5 um-thickness (10 um-thickness preferred) that contain no less than 1 mm² of TUMOR tissue.

• For tumor areas less than 5 mm² -- send at least 8 USS
• For tumor areas greater than or equal to 5 mm² -- send at least 5 USS

Acceptable specimen types:

• An FFPE block of solid tissue
• FFPE cell buttons from fine needle aspirates (FNA), including bone marrow aspirates
• FFPE cell buttons from malignant effusions
• FFPE core needle biopsies
• Unstained slides from any of the above

Unacceptable specimen types:

• Tissue that has been decalcified
• Any unfixed tissues or fluids
• Wet or frozen tissue, or tissue that has been previously frozen
• Tissue pre-embedded in agar
• Blood or urine

For all specimen types, please ensure that:

• Tissue does not sit on bench for more than 1 hour before fixation
• Tissue is fixed in phosphate buffered formalin for between 6 and 24 hours 

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References