Lack of EGFR gene mutations in exons 19 and 21 in esophageal (Barrett's) adenocarcinomas.

Epidermal growth factor receptor is over-expressed in several tumors and is the target for the tyrosine kinase inhibitor gefitinib. This receptor is also over-expressed in esophageal adenocarcinomas. In non-small cell lung cancer, specific somatic mutations residing in the epidermal growth factor receptor tyrosine kinase in the activation loop and the glycine-rich P-loop, are responsible for an enhanced sensitivity toward gefitinib. We analyzed exons 19 and 21 coding for the receptor tyrosine kinase of the epidermal growth factor gene in 105 samples of esophageal (Barrett's) adenocarcinoma by denaturing high-pressure liquid chromatography. We found only one silent mutation in exon 19 of adenine to guanine in codon 754 leading to a substitution of K to K, the rest of the sample being wild-type genotype. In conclusion, mutations within the tyrosine kinase domain of EGFR associated with sensitivity of non-small cell lung cancer patients to gefitinib are not present in esophageal (Barrett's) adenocarcinoma.