Gene

Targeted therapy

Biology

Gefitinib

Adenocarcinoma

H&E stain

EGFR inhibitors

Lung cancer

Cancer research

Genetics

Epidermal growth factor receptor

Internal medicine

Oncology

Medicine

Exon

Gene duplication

Immunohistochemistry

Cancer

Afatinib

Pathology

Journal of Thoracic Oncology

Oncogenic mutations in the epidermal growth factor receptor (EGFR) are found in a subset of patients with non-small cell lung cancer (NSCLC) and serve as important predictive biomarkers in this disease. EGFR exon 18-25 kinase domain duplication (EGFR-KDD) mutations has rencently emerged as a new EGFR gene molecular subtype in non-small cell lung cancer(NSCLC) is extremely rare. A 59-year-old male diagnosed with adenocarcinoma, who was shown to have gene detected by the next generation sequencing (NGS)and treatment with afatinib. Histopathological observations with hematoxylin and eosin staining was shown adenocarcinoma, immunohistochemical staining for the expression of TTF-1, NapsinA and CK7. The gene detected by NGS that found an EGFR-KDD, CTNNB1 p.S37Y and TP53 p.R282W. Our case is the second report EGFR-KDD in Chinese populations. The patient was treated with afatinib therapy. And afatinib therapy showed a good response. The cases presented here highlight that adjusting our strategy and using newly available tools, such as comprehensive NGS tests, could prove useful in detecting alternative ways in which the EGFR pathway is altered (and can be targeted) in tumors.

P3.CR-12 A Novel Oncogenic Driver in a Lung Adenocarcinoma Patient Harboring an EGFR-KDD and Response to Afatinib