Targeted cancer therapies are defined as antibody or small molecule drugs that block the growth and spread of cancer by interfering with specific cell molecules involved in tumor growth and progression. Multiple targeted therapies have been approved by the US Food and Drug Administration (FDA) for treatment of specific cancers. Molecular genetic profiling is often needed to identify targets amenable to targeted therapies and to minimize treatment costs and therapy-associated risks.

Rondell P. Graham, M.B.B.S., gives an overview of this test available through Mayo Clinic Laboratories. He discusses when this testing should be ordered, how this testing compares to other testing approaches, and what clinical action can be taken due to the results of this testing.

Testing

Useful for:

  • Identifying tumors that may respond to targeted therapies by assessing multiple gene targets simultaneously
  • Identifying mutations that may help determine prognosis for patients with solid tumors
  • Identifying specific mutations within genes known to be associated with response or resistance to specific cancer therapies

Specimen Requirements

Advisory Information

At least 20% tumor is required for this assay. The amount of tissue needed is dependent on a variety of preanalytical factors (eg, cellularity, ischemic time, fixation). In general, the minimum specimen adequacy for this test is approximately a 6 mm(2) area of tissue (can be over multiple slides from one tissue block) or 5,000 total cells (5,000 total nucleated cells if using cytology slides).

Necessary Information

A pathology report must accompany specimen in order for testing to be performed.

Specimen Required 

Preferred:

Specimen Type: Tissue

Container/Tube: Tissue block

Collection Instructions: Submit a formalin-fixed, paraffin-embedded tissue block.

Acceptable:

Specimen Type: Tissue

Slides: 1 stained and 10 unstained

Collection Instructions: Submit 1 slide stained with hematoxylin and eosin and 10 unstained, unbaked slides with 5-micron thick sections of the tumor tissue.

Acceptable:

Specimen Type: Cytology

Container/Tube: Cytology slide (Direct smears or ThinPrep)

Slides: 1-2 slides (stained and coverslipped) with a minimum of 5,000 total nucleated cells

Collection Instructions: Submit 1-2 slides stained and coverslipped.

Additional Information: Cytology slides will not be returned.

Performance Information

Day(s) and Time(s) Test Performed 

Monday through Friday; Varies

Analytic Time 

12 days

alyssafrank

Alyssa Frank

Alyssa Frank is a Marketing Segment Manager at Mayo Clinic Laboratories. She leads marketing strategies for product management and specialty testing. Alyssa has worked at Mayo Clinic since 2015.

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