Advanced Lung Adenocarcinoma Patient withERBB2Amplification Identified by Comprehensive Genomic ProfilingBenefits from Trastuzumab

For non-small-cell lung cancer ( patients without established actionable alterations in genes such asEGFRorALK, optionsfor targeted therapy remain limited in clinical practice. About 5% of lung adenocarcinoma patients have tumors withERBB2genetic alterations, with even fewer patients harboringERBB2amplification. Currently, clinical trials mainly use , ormutation testing to identify potential responders to ERBB2-targeting agents. The use of next-generation sequencing (NGS) todetectERBB2alterations, including copy number variants, is rare. In this study, we present an EGFR- and ALK-negativeadvanced NSCLC case for which we conducted comprehensive tumor genomic profiling to identify potentially actionablealterations. The tumor harbored anERBB2amplification, and trastuzumab-based therapy resulted in an excellent response, witha necrotic regression of the patient’s lung lesion. Although he developed brain metastasis four months after trastuzumabinitiation, he survived for an additional period of eight months without local recurrence or other systemic metastasis. This casereport shows that the use of comprehensive genetic testing enables the identification of rare actionable alterations in NSCLCpatients without other options for targeted treatment.