EGFR

EGFR mutation common on EXON 19 and 21

Studies have earlier identified specific activating mutations within the tyrosine kinase domain of EGFR. These studies demonstrated that most of these deletions accounting for mutation overlapped by sharing the deletion of four amino acids within exon 19. These studies also demonstrated amino acid substitution within exon 21: leucine to arginine at codon 858 (L858R) and leucine to glutamine at codon 861 (L861Q). Somatic mutations in the EGFR gene are detected in approximately 30 to 40% of non–small-cell lung cancers (NSCLCs) from Asian patients and in 10% of NSCLCs from white patients.

These mutations in EGFR exon 19 and 21 (particularly L858R) now serve as the molecular correlate of the dramatic responses observed in patients being treated with TKIs (Tyrosine Kinase Inhibitors).


References:

  • Lynch, T.J., Bell, D.W., Sordella, R., Gurubhagavatula, S., Okimoto, R.A., Brannigan, B.W., Harris, P.L., Haserlat, S.M., Supko, J.G., Haluska, F.G. and Louis, D.N., 2004. Activating mutations in the epidermal growth factor receptor underlying responsiveness of non–small-cell lung cancer to gefitinib. New England Journal of Medicine, 350(21), pp.2129-2139.

  • Keedy, V.L., Temin, S., Somerfield, M.R., Beasley, M.B., Johnson, D.H., McShane, L.M., Milton, D.T., Strawn, J.R., Wakelee, H.A. and Giaccone, G., 2011. American Society of Clinical Oncology provisional clinical opinion: epidermal growth factor receptor (EGFR) mutation testing for patients with advanced non–small-cell lung cancer considering first-line EGFR tyrosine kinase inhibitor therapy. Journal of clinical oncology, 29(15), pp.2121-2127.

More information about the drug treatment options

Tarceva(Erlotinib)


Gilotrif (Afatinib)


Tagrisso (Osimeritib)


Vizimpro (Dacomitinib)