Epidermal growth factor receptor gene mutations in early pulmonary adenocarcinomas.

BACKGROUND Epidermal growth factor receptor (EGFR) gene mutations are frequently found in pulmonary adenocarcinomas. MATERIALS AND METHODS Various lung cancers (n=30) including 8 small adenocarcinomas were examined for EGFR gene mutations in three exons. RESULTS Mutations were detected in 32% of adenocarcinomas. Exon 19 mutations were detected in 5 tumors, often advanced stages: 1 in Noguchi's pathologic type C, 2 in type D, and 2 in type F. Exon 21 mutations were detected in 3 tumors, all small adenocarcinomas in type C, at pathologic stage IA. CONCLUSION We suspect that exon 21 mutations are early events in small bronchioloalveolar carcinomas, while exon 19 mutations are later events occurring in adenocarcinomas of various types.