The human epidermal growth factor receptor (EGFR) gene in European patients with advanced colorectal cancer harbors infrequent mutations in its tyrosine kinase domain
1 Laboratoire de Recherche sur le Cancer et les Maladies du Sang, 4, rue Ernest Barblé L-1210 Luxembourg, Luxembourg
2 Département d'anatomie pathologique, Université de Liège, Avenue de l'Hôpital, 1 (B34), GIGA-Research, CHU Sart-Tilman, 4000 Liège, Belgium
3 Service de Chirurgie, Clinique Ste Thérèse, ZithaKlinik, 36, rue Sainte Zithe, L-2763 Luxembourg, L-2763 Luxembourg
4 Service d'Hémato-Cancérologie, Centre Hospitalier, 4, rue Ernest Barblé L-1210 Luxembourg Luxembourg
BMC Medical Genetics 2011, 12:144 doi:10.1186/1471-2350-12-144Published: 25 October 2011
The epidermal growth factor receptor (EGFR), a member of the ErbB family of receptors, is a transmembrane tyrosine kinase (TK) activated by the binding of extracellular ligands of the EGF-family and involved in triggering the MAPK signaling pathway, which leads to cell proliferation. Mutations in the EGFR tyrosine kinase domain are frequent in non-small-cell lung cancer (NSCLC). However, to date, only very few, mainly non-European, studies have reported rare EGFR mutations in colorectal cancer (CRC).
We screened 236 clinical tumor samples from European patients with advanced CRC by direct DNA sequencing to detect potential, as yet unknown mutations, in the EGFR gene exons 18 to 21, mainly covering the EGFR TK catalytic domain.
EGFR sequences showed somatic missense mutations in exons 18 and 20 at a frequency of 2.1% and 0.4% respectively. Somatic SNPs were also found in exons 20 and 21 at a frequency of about 3.1% and 0.4% respectively. Of these mutations, four have not yet been described elsewhere.
These mutation frequencies are higher than in a similarly sized population characterized by Barber and colleagues, but still too low to account for a major role played by the EGFR gene in CRC.