Điều trị osimertinib kết hợp hóa trị bước một trong ung thư phổi không tế bào nhỏ giai đoạn IV có đồng đột biến EGFR L858R và khuếch đại HER2 de novo: Báo cáo ca lâm sàng

Abstract

Concurrent de novo HER2 amplification with EGFR mutation in non-small cell lung cancer (NSCLC) is a rare condition, biologically distinct from acquired HER2 amplification, which drives resistance to tyrosine kinase inhibitors (TKIs). First-line osimertinib plus chemotherapy is the preferred regimen for patients with advanced EGFR-mutant NSCLC; however, its efficacy in patients with concurrent de novo HER2 amplification remains unclear. Case report: A 76-year-old male, never-smoker, was diagnosed with stage IV NSCLC. Next-generation sequencing (NGS) identified concomitant EGFR L858R mutation and de novo HER2 amplification. The patient received first-line osimertinib combined with carboplatin-pemetrexed, followed by osimertinib-pemetrexed maintenance, achieving a partial response at 3 months that was sustained through month 12, with good tolerability and no serious adverse events. Conclusion: First-line osimertinib plus chemotherapy provides effective disease control with an acceptable safety profile in NSCLC patients harboring concurrent EGFR L858R mutation and de novo HER2 amplification.