EGFR by ARMS PCR

Function

The EGFR (Epidermal Growth Factor Receptor) mutation test using ARMS PCR (Amplification Refractory Mutation System) is a molecular diagnostic tool. It identifies specific mutations in the DNA of tumor cells. In certain cancers, the EGFR protein is overactive, causing cells to divide uncontrollably. ARMS PCR is a highly sensitive method capable of detecting low levels of mutant DNA in a background of wild-type (normal) DNA.

Why it is Ordered

This test is vital for patients diagnosed with Non-Small Cell Lung Cancer (NSCLC), particularly adenocarcinomas. It is used to:

• Select Targeted Therapy: Patients with specific EGFR mutations (like Exon 19 deletions or L858R) respond exceptionally well to Tyrosine Kinase Inhibitors (TKIs) like Osimertinib or Erlotinib.
• Identify Resistance: Detecting the T790M mutation helps explain why a patient might stop responding to first-generation TKIs.

Associated Conditions

• NSCLC (Non-Small Cell Lung Cancer): The primary condition where EGFR testing is standard of care.
• Adenocarcinoma: The histological subtype most likely to harbor these mutations.

Determining the EGFR status is a cornerstone of personalized medicine, allowing clinicians to bypass standard chemotherapy for more effective, targeted treatments.