Excellent response to erlotinib in breast carcinoma with rare EGFR mutation-a case report

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Triple-negative breast carcinoma (TNBC) presents significant therapeutic challenges due to limited treatment options and poor prognosis.
• Epidermal Growth Factor Receptor (EGFR) overexpression is observed in a subset of TNBC patients, suggesting its potential as a therapeutic target.
• Tyrosine kinase inhibitors (TKIs) are being investigated for their efficacy against EGFR-driven malignancies.

Observation:

• A diagnostically complex case of metastatic breast carcinoma with extensive lung involvement and poor Eastern Cooperative Oncology Group (ECOG) performance status was analyzed.
• The patient's tumor exhibited an uncommon EGFR mutation, specifically Exon 21 L861Q.
• Standard treatment modalities had been exhausted without significant benefit.

Findings:

• The patient received erlotinib, an EGFR tyrosine kinase inhibitor, following the failure of all primary treatment modalities.
• Remarkable clinical benefit was observed with erlotinib treatment.
• This case demonstrates the successful application of targeted therapy for an unusual EGFR mutation in breast cancer.

Implications:

• The findings underscore the presence of rare EGFR mutations in breast carcinoma, necessitating comprehensive molecular profiling.
• Molecular analysis and tailored targeted therapy are crucial for optimizing treatment strategies, particularly in patients with poor performance status.
• Targeted therapy offers a valuable problem-solving approach for refractory or advanced breast cancer cases.