Co-Occurring EGFR L858R Mutation and HER2 Amplification in NSCLC Identified by Stepwise Molecular Profiling.
Rabiga Kadyrbayeva, Dilyara Kaidarova, Aisha Moldasheva et al.
✦ AI-curated · Sources linked
Case in brief
A 54-year-old non-smoking woman with Stage IIIA lung adenocarcinoma initially tested negative for EGFR mutations. After disease progression and severe chemotherapy toxicity, stepwise molecular profiling revealed HER2 amplification, leading to 23 months of stabilization on trastuzumab. Subsequent next-generation sequencing identified an EGFR L858R mutation, prompting a treatment change to gefitinib after new lung lesions developed.
What made this case unusual
The case highlights the coexistence of EGFR L858R mutation and HER2 amplification, which were not detected by initial PCR testing, emphasizing the limitations of conventional molecular testing.
Diagnostic / clinical pearl
Clinicians should consider stepwise molecular profiling in cases of NSCLC with negative initial tests, as it may reveal co-occurring actionable mutations.
Why it matters
This case underscores the importance of comprehensive molecular testing in identifying multiple oncogenic drivers, which can significantly impact treatment strategies in lung cancer management.