7176 Background: Recent studies have suggested that EGFR mutations can be used to predict tumor sensitivity to gefitinib (epidermal growth factor receptor tyrosine kinase inhibitor) in patients with non-small-cell lung cancer (NSCLC). Most previous studies of EGFR mutations have used direct sequencing to analyze surgically resected specimens. More rapid, accurate, and simple techniques for analysis of EGFR mutations in histologic or cytologic specimens (i.e., transbronchial biopsy, bronchial washing, pleural effusion, lymph node aspiration) are needed to improve outcomes. Methods: DNA was extracted from histologic or cytologic specimens of NSCLC obtained from March through October 2005. The major mutations of the EGFR gene (exons 18–21) were analyzed by our original technique for fragment analysis and polymerase-chain-reaction-restriction-fragment-length polymorphism analysis. Results: About 2 days were required for mutation analysis. Pathological analysis indicated that 64 (5 histologic and 59 cytologic specimens) of 90 specimens (11 histologic and 79 cytologic specimens) were adenocarcinomas. EGFR mutations were found in 22 of these specimens (2 histologic and 20 cytologic specimens; ex19:del 13, ex19:ins 2, ex21:L858R 7). An EGFR mutation (ex19:del) was also found in a patient with large cell carcinoma. Conclusions: Our method can efficiently detect EGFR mutations in small samples of lung cancer cells obtained from histologic or cytologic specimens. This method is useful for the identification of EGFR mutations in patients with unresectable NSCLC in whom sufficient tissue specimens are difficult to obtain. No significant financial relationships to disclose.
Negative NKX2-1 (TTF-1) as Temporary Surrogate Marker for Treatment Selection During EGFR-Mutation Analysis in Patients with Non–Small-Cell Lung Cancer
