Trial Information

Study of KRAS Mutation in 250 Cases of Colorectal Carcinoma and Study of the Incidence of the Disease in Martinique, From 2007 to 2009

- The colorectal carcinogenesis is complex. It influences among others, the EGFR
(Epidermal Growth Factor Receptor) which activation leads to tumoral proliferation,
differentiation and invasion. The binding of the EGF (Epidermal Growth Factor) or of
another ligand to the EGFR is responsible for the activation of the Ras- Raf and Pi3k
pathways.

- The mutation of the genes KRAS, BRAF or PIK3CA results in their continuous activation,
independently of the activation or of the pharmacological blocking of EGFR. The most
frequently found mutation affects the KRAS gene (20 to 50 % of the cases). 90 % of
these mutations are situated on codons 12 and 13 of this gene (70 % codon 12 and 30 %
codon 13). These mutations are responsible for a decrease of the GTPase activity of the
ras protein, which stays then in active conformation bound to the GTP. This leads to
the blocking of the pathway and to the inactivity of the pharmacological blocking of
EGFR.