Small Cell Lung Cancer with Mutation of Epidermal Growth Factor Receptor in Patients with Lung Adenocarcinoma Resistant to Gefitinib / 대한내과학회지

ABSTRACT

Most epidermal growth factor receptor (EGFR) gene mutations are detected in lung adenocarcinomas. In contrast, these mutations have rarely been reported in small cell lung cancer (SCLC). We herein report two cases of EGFR-mutant SCLC transformed from and combined with lung adenocarcinoma. In one case, SCLC appeared to be transformed from EGFR mutant 19-del adenocarcinoma when the patient became resistant to gefitinib. The other patient had combined EGFR-mutant 19-del SCLC and adenocarcinoma at the initial diagnosis, which was resistant to gefitinib at multiple sites. Further comparative molecular analyses of these histologically distinct tumors would provide useful information regarding the role of EGFR mutation in the pathogenesis of SCLC. In conclusion, despite the presence of the same EGFR mutation, gefitinib was not effective in treatment of SCLC. Therefore, confirmation of SCLC cell morphology may become an important means of predicting resistance to EGFR tyrosine kinase inhibitors in addition to common secondary genetic alterations.