Resistance to gefitinib

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Non-small cell lung cancer (NSCLC) patients with specific epidermal growth factor receptor (EGFR) mutations often respond to tyrosine kinase inhibitors (TKIs) like gefitinib.
• Despite initial efficacy, acquired resistance frequently leads to treatment relapse in these patients.

Observation:

• A case study of advanced NSCLC with an EGFR delE746-A750 mutation treated with gefitinib is presented.
• The patient experienced initial dramatic improvement followed by relapse.

Findings:

• A secondary EGFR T790M mutation was identified in tumor biopsy from the relapse site.
• This T790M mutation was not present in the pre-treatment tumor biopsy, indicating acquired resistance.

Implications:

• Screening for EGFR mutations aids in identifying patients suitable for gefitinib therapy.
• The emergence of acquired resistance mutations like T790M highlights the need for developing alternative or combination therapies for NSCLC.