EGFR Mutation Detection Test (EXONS 18, 19, 20, 21) in Kurla

A positive result is an indicator of the presence of EGFR mutations and TKI therapy can be effective on this person with non-small lung cancer.

However, a negative result does not necessarily mean that there is the absence of EGFR mutation. The particular patient may still harbor an EGFR mutation. The patient with a negative result with this test should be considered for mutation testing of a tissue specimen for EGFR mutations. The limit of detection of this assay for the detection of EGFR mutations is affected by the amount of cell-free DNA in the blood.

Your healthcare provider may ask you to take this test if you have been diagnosed with non-small lung cancer and tyrosine kinase inhibitors (TKIs) are being considered for the treatment. It has been demonstrated in several studies that EGFR gene mutations act as an important marker to effectively select patients for the treatment with TKIs. That said, the effectiveness of EGFR-targeted therapy in non-small cell lung cancer patients is restricted to patients whose tumors possess mutations in the EGFR gene.

Lung cancers are one of the leading causes of death in developed countries. Unfortunately, 60% of non-small lung cancers are high-stage or advanced tumors by the time they are detected. The majority of them already get metastasized and become inoperable tumors before diagnosis.

On the other hand, approximately 25% of non-small cell lung cancers have mutations in the EGFR gene and most mutations exist in hotspot regions in exons 18, 19, 20, and 21 of this gene. Therefore, the discovery of mutations in the EGFR gene that have the potential to make the tumor sensitive to tyrosine kinase inhibitors (TKIs) treatment has become one of the most crucial breakthroughs in the field of oncology in the past decade.

Various researches have shown that the response rate to the TKIs such as Erlotinib or Gefitinib as first-line treatment in patients with EGFR mutated non-small lung tumors is far superior in comparison to the conventionally used chemotherapy. Hence, these two drugs have been approved by the FDA for use in the treatment of patients with non-small lung cancer who previously did not respond well to chemotherapy.