RESUMO
AIM: Activating mutations in the epidermal growth factor receptor (EGFR) are predominantly detected in pulmonary adenocarcinoma and have been reported in small cell lung cancer (SCLC) for decades. This retrospective single-center study aimed to determine the frequency and types of EGFR mutations in SCLC in Taiwan. METHODS: This study comprises a consecutive cohort of 161 patients histologically diagnosed with SCLC between January 1992 and August 2014 at the Department of Pathology in Keelung Chang Gung Memorial Hospital, Taiwan. Archived formalin-fixed paraffin-embedded sections from 71 patients were eligible for molecular analysis. EGFR mutation analysis was performed using a fully-automated IdyllaTM EGFR Mutation Test and confirmed a comparable result through Qiagen Therascreen® EGFR RGQ PCR. In addition, EGFR gene copy number was assessed in EGFR-mutated tumors by fluorescence in situ hybridization (FISH). RESULTS: Mutational status of the EGFR gene was successfully analyzed in 63 specimens by both IdyllaTM and Qiagen platforms. Both methods detected L858R point mutation in exon 21 in an 81-year-old female and a 47-year-old male non-smoker. Both tumors show no concurrent EGFR gene amplification. The overall agreement between results obtained with the Idylla™ EGFR Mutation Test and Qiagen Therascreen® EGFR RGQ PCR was 100% Conclusions. Our results showed that EGFR mutation is a rare mutation type in a consecutive series of de novo SCLC. Furthermore, the performance of Idylla™ EGFR Mutation Test and Qiagen Therascreen® EGFR RGQ PCR on archived paraffin sections of limited quantities is available with the high agreement of results.
Assuntos
Receptores ErbB , Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Feminino , Humanos , Masculino , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Análise Mutacional de DNA/métodos , Receptores ErbB/genética , Formaldeído , Hibridização in Situ Fluorescente , Neoplasias Pulmonares/diagnóstico , Mutação , Parafina , Estudos Retrospectivos , Carcinoma de Pequenas Células do Pulmão/diagnóstico , Carcinoma de Pequenas Células do Pulmão/genéticaRESUMO
Response to gefitinib is strongly associated with the status of the epidermal growth factor receptor gene. Here we report the different treatment responses in a case of lung adenocarcinoma coexpressing mutant-type gene in the primary lung mass and a wild-type gene in the metastatic bone lesions. This case demonstrated that at least two strains of tumor cells were present in a single patient. This may be one of the mechanisms of gefitinib resistance.
