2018 Volume 67 Issue 4 Pages 503-511
The RAS gene mutation test is extremely important when determining whether the use of molecular target drugs in colorectal cancer treatment is appropriate and in selecting the treatment method. Here, we report on our comparison of RAS with RASKET, which is an IDV reagent, by establishing a RAS mutation measurement method using the genetic analyzer i-densy IS-5320. The subjects included 21 colorectal cancer patients at our hospital, and Mutation tests of KRAS exons 2, 3, and 4 and NRAS exons 2 and 3 were conducted using a paraffin block designated for genetic tests. The results were in agreement with those of RASKET in terms of the presence of RAS mutation as well as all mutation regions. Even in minor mutations in which the mutation frequency was low, the results showed good agreement. Efficiency and simplification of the work were realized by keeping the measurement time within 120 min using a Multitype UNIVERSAL reagent. Moreover, because this measurement method allowed us to conduct BRAF gene mutation tests at the same time, it improved the coverage rate of anti-EGFR drug resistance mutations in colorectal cancer and was suggested to provide important information on colorectal cancer treatment. Finally, the analytic validity of this measurement method was equivalent to that of the IVD method and it was sufficiently available in routine laboratory tests, leading us to believe that it is an extremely useful method.
