EGFR Exon 18-21 mutation analysis
Exons 18–21 of the EGFR gene should be analysed for mutations, as this is where the EGFR mutations are clustered (Sharma 2007)
EGFR mutation testing involves the patient, physician and pathologist. The following diagram shows the role each person plays during testing:
The EGFR Test Guide slide kit explaining how to test for EGFR mutations can be downloaded here
Pathology review
The tumour sample should be examined by a pathologist to ensure that tumour cells are present.
If possible the sample should be macrodissected to enrich the tumour DNA for analysis. This decreases the risk of false negative results (Eberhard 2008)
Mutation analysis
- After the pathologist has examined the tumour sample, DNA extraction and mutation analysis is carried out to determine whether the tumour contains mutated EGFR
- Different methodologies can be used and examples include PCR (polymerase chain reaction), gene sequencing and ARMS (Amplification Refractory Mutation System)
Reporting results to the doctor
The presence and type of EGFR mutation found in testing should be reported to the doctor.
An example EGFR mutation report form can be downloaded here