What is EGFR mutation test and what is immunoreactive score implies?

sachin270588

My father is suffering from lung cancer(stage 4). After biopsy test his slides were gone for EGFR mutation test. And he got immunoreactive score of 4+ after this test.
Doctor told me that after this test they will going to conclude that if he will be treated with gefitnib or chemotherapy. What does this test implies???

Booster24

I believe this means if he
I believe this means if he tested positive for the EGFR mutation he could use a non-chemo treatment. This happens in roughly 50% of patients.