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

Gefitinib에 내성을 보인 폐선암에서 발견된 Epidermal Growth Factor Receptor 돌연변이 양성인 소세포폐암

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.

저자들은 처음 EGFR 변이 양성인 선암으로 진단되어 EGFR TKI사용 후 저항성을 보였으며 진행된 병변에서 재조직검사를 시행하여 같은 EGFR변이 양성 소세포암으로 판명된 발병기전이 서로 다를 것으로 생각되는(transformed and combined) 증례 2예를 경험하였기에 문헌고찰과 함께 보고하는 바이다.