EGFR Mutation Detection (Exons -18, 19, 20, 21), FFPE Tissue

EGFR Mutation Test Overview

The EGFR mutation test is a crucial diagnostic tool that identifies specific genetic alterations in the Epidermal Growth Factor Receptor (EGFR) gene, particularly in exons 18, 19, 20, and 21. This test is primarily used to detect these mutations in patients with Non-Small Cell Lung Cancer (NSCLC), especially those with adenocarcinoma. By identifying the presence of EGFR mutations, the test helps determine whether a patient's tumour is likely to respond to targeted therapies such as Tyrosine Kinase Inhibitors (TKIs).

The EGFR mutation analysis provides valuable insights into the molecular characteristics of the tumour, enabling healthcare professionals to develop personalised treatment plans. By identifying patients who are likely to benefit from TKIs, the test helps optimise treatment outcomes and improve overall patient care. Additionally, the test can provide information about the aggressiveness of the disease and predict the patient's response to specific targeted therapies.

EFGR mutations are most commonly seen in Non-Small Cell Lung Cancer (NSCLC) adenocarcinomas. EFGR mutations tend to occur in women with little or no smoking history. The doctor may recommend testing if they suspect one has lung cancer. A biopsy is recommended if a person is already diagnosed with lung cancer, or if there is a recurrence of tumours in the patient.
Up to 20% of NSCLC tumors harbour the EGFR mutation in Exons 18-21, and that ~85% of patients with these patients respond to TKI treatment.

It’s pertinent that anyone with a diagnosis of lung cancer or those who are suspected of the disease should ask their doctor whether to get tested for EFGR. The doctor can use the same biopsy tissue used to diagnose lung cancer for testing for mutations.

Exons and introns are nucleic acid sequences made up of the polynucleotide chain. However, the structure of introns is more complex with high GC-rich regions and repetitive sequences. Both the exons and introns take part in protein formation and follow the DNA packaging mechanism to fit inside a cell.

Written by: Dr Vishal Wadhwa, M.D, D.N.B Microbiology, Medical Affairs