A comparability study of 5 commercial KRAS tests

Area of Science:

• Oncology
• Molecular Diagnostics
• Genetics

Background:

• Activating KRAS gene mutations are common in colorectal carcinomas, particularly at codons 12 and 13.
• KRAS mutations are linked to reduced efficacy of anti-epidermal growth factor receptor therapies.
• Accurate KRAS mutational status analysis is crucial for guiding treatment strategies.

Purpose of the Study:

• To assess the concordance of KRAS mutation detection across multiple laboratories.
• To compare commercial KRAS assay results with direct sequencing methods.

Main Methods:

• Forty colorectal cancer tumor samples were analyzed.
• Samples were tested by five commercial laboratories and one central laboratory using direct sequencing.
• Kappa statistics were used to compare agreement between assays.

Main Results:

• KRAS mutations in codons 12/13 were found in 50% of samples by direct sequencing.
• HistoGeneX, Genzyme, and Agencourt assays showed almost perfect agreement (kappa > 0.94) with direct sequencing.
• Gentris showed substantial agreement (kappa = 0.75), while Invitek showed slight agreement (kappa = 0.13).

Conclusions:

• Most commercial KRAS testing services provide accurate and comparable results to direct sequencing.
• Variability exists among commercial KRAS assays, highlighting the need for careful selection.
• Reliable KRAS mutation analysis is achievable with select commercial laboratory services.