KRAS testing in clinical laboratory: optimizing targeted therapy.

BACKGROUND/AIM: Activating mutations in the KRAS gene are found in more than 30% of colorectal tumors, where they are associated with a poor response to anti-epidermal growth factor receptor therapies. Mutation testing techniques have therefore become an urgent concern. Several methods for KRAS mutation detection have been described in the literature. Most of these are laboratory developed tests and only a few commercial assays are currently available.

MATERIALS AND METHODS

We studied the performance characteristics of a KRAS mutation detection assay on the ABI-3130XL genetic analyzer using a new commercial mutation detection kit based on shifted termination assay technology. Samples were analyzed in parallel by different reference laboratories using alternative methodologies. Various sample types were used including formalin-fixed paraffin-embedded tissue, fine-needle aspirates, and cyst fluid specimens.

RESULTS

A high level of agreement (100% correlation for formalin-fixed paraffin-embedded tissue and fine-needle aspirate samples and 93% correlation for cyst fluid specimens) was obtained despite the use of different methodologies.

CONCLUSION

Shift termination assay is a simple, robust, and sensitive method for the identification of KRAS mutations in a wide variety of specimen types.