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KRAS Mutation Assay

Reference Number: AA-00311

SECTION EIGHT

Dahl-Chase Diagnostic Services

MOLECULAR PATHOLOGY TESTING

KRAS MUTATION ASSAY

Clinical Significance:

 

The American Society of Clinical Oncologists (ASCO) recommends routing testing for KRAS mutations for all colorectal carcinomas considered for therapy with cetuximab.  Of all known KRAS mutations, the vast majority have been identified in human cancers involving codons 12 and 13 of KRAS.  An estimated 30-40 percent of colorectal carcinomas carry mutant forms of the gene KRAS.  Patients with advanced colorectal carcinoma who have such mutations should not receive the epidermal growth factor (EGFR) antibody therapy.

 

 

Specimen Requirements and Collection:

Formalin fixed tissue containing a sufficient amount of tumor (generally at least several mm of tumor tissue submitted in the tissue block).  The KRAS test utilized by our laboratory will detect mutations as long as they constitute at least 25% of the DNA sample mix.

 

Forms:

Molecular Pathology requisition form

 

Transport:

Send paraffin block containing tumor at room temperature

 

Reference Range:

KRAS mutation not detected = negative result

KRAS mutation detected = positive result

 

 

CPT codes:

88381, 81275, 81403, G0452

 

 

 

Test reported:

Results are reported within 7-10 days