Sorafenib With Irinotecan in Metastatic Colorectal Cancer (mCRC) and K-RAS Mutation

Inclusion Criteria: * Age \> 18 * Written informed consent * Histologically proven adenocarcinoma of the colon or rectum asymptomatic primary tumour or surgically removed mCRC patients with previously unresectable metastatic disease * Patient with at least one tumoral lesion: measurable in a unidimensional way with a spiral scanner according to RECIST, no previous irradiation in this area * Disease progression after irinotecan-based chemotherapy * Disease progression after one or more previous lines of chemotherapy received in metastatic situation * WHO \<= 2 * Patient having a mutated KRAS on 12 or 13 codons on the primary tumour or a metastasis * Adequate liver function : Bilirubin ≤ 1,5 x UNL, ASAT ou ALAT ≤ 2,5 x UNL (or \< 5 x UNL for subjects having a hepatic insufficiency in connection with hepatic metastases) * Polynuclear neutrophils ≥ 1 500/mm3 * Haemoglobin \> 10g/dl * Platelets ≥ 100 000/mm3 * Amylase and lipase \< 1,5 x UNL * Serum Creatinin \< 1,5 x UNL * Adapted contraceptive measures during treatment and continued at least three months after end of the treatment * Life expectancy \> 3 months * Affiliated to or benefiting from health insurance Exclusion Criteria: * Gilbert's disease * Brain metastases or carcinomatous symptomatic meningitis * Exclusive bone metastasis * Previous cancers not considered as cured in the 5 years before inclusion (except for baso-cellular skin carcinoma) Surgery (except diagnostic biopsy) or radiotherapy within 4 weeks before inc…