Establishment of a technical protocol for EGRF mutation testing in patients with non-smal cell lung cancer (NSCLC)

Abstract

Objective: Develop a standard technical procedure for testing to determine EGFR gene mutations from paraffin cast samples. Methods: Cross-sectional descriptive study, using Realtime-PCR technique in the process of determining gene mutations. Six paraffin cast tissue samples FFPE of patients diagnosed with lung cancer by histopathology and identified with EGFR gene mutations by molecular biology techniques were used to develop the procedure. Apply the procedure to detect EGFR gene mutations after being built on 109 paraffin cast samples FFPE of patients diagnosed with lung cancer by histopathology.  Results: With 4-5 slices for each sample, the DNA concentration obtained ensures the quantity and input sample for the gene amplification reaction. When soaking in xylene twice in a row with each soaking time of 5 minutes under shaking and incubation conditions at 560C, the sample completely removed Paraffin, ensuring the purity of the input DNA of the gene amplification reaction. Of the 109 specimens tested, 38 were positive. Of these, 1 specimen was positive for both S768I and G719C; L858R had the highest positive rate of 31.58%, followed by ex19del at 28.95%; G719x and EGFR S768I both had a rate of 10.53%; EGFR ex20ins accounted for 7.89%, and finally EGFR T790M and EGFR L861Q accounted for 5.26%. Conclusion: Standardization and successful construction of the technical process for testing to determine EGFR gene mutations. The process gives higher test results, suitable for the facilities and equipment at the hospital. The rate of NSCLC patients identified to carry EGFR gene mutations of 34.86% is quite high.