Detection of the EGFR mutation in exhaled breath condensate from a heavy smoker with squamous cell carcinoma of the lung.

A 61-year-old male smoker (40 pack-years) presented with right chest pain. Computed tomography of the chest revealed a cavitary mass in the right lower lobe. A transbronchial biopsy showed squamous cell carcinoma. We examined epidermal growth factor receptor (EGFR) mutations in exhaled breath condensate (EBC). The DNA extracted from his EBC showed a deletion mutation in exon 19. Subsequently, the del E746-A750 mutation in exon 19 in a transbronchial tissue specimen was confirmed. Although he underwent whole-brain irradiation against multiple brain metastases, he had paralysis of the left side of the body and his performance status was 3. The patient was treated with gefitinib. He had marked tumor regression and no symptoms. Although only a small percentage of heavy smokers with squamous cell carcinoma harbor EGFR mutations, they probably benefit from EGFR-tyrosine kinase inhibitors. EGFR mutation status in the patients having such clinical features might be examined.