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.