Inclusion Criteria:

- Patients with metastatic colorectal cancer (confirmed histologically) with objective
response or stabilization after at least 6 cycles of first line chemotherapy
(treatment of choice is selected freely by the investigator according to the
recommendations and consensus in force),

- The interval between completion of first line chemotherapy and randomization should
not exceed 4 weeks

- Age>18 years

- ECOG status 0 to 2

- Biological criteria prior to any chemotherapy:

Neutrophils>1.5 109 g/l, platelets>100 109/l, haemoglobin>10 g/dl, Creatininaemia<150
mol/l, bilirubinaemia<2x normal level

- Signed informed consent

- Life expectancy > 3 months

Exclusion Criteria:

- Metastatic colorectal cancer treated with more than one modality of first line
chemotherapy (including oral fluoropyrimidines)

- Tumour progression after first line chemotherapy or before randomization

- Other tumour pathology

- Symptomatic cerebral metastases

- Any severe uncontrolled disease in addition to colorectal cancer (in particular
decompensated cardiac failure (LVEF<50%) or coronary insufficiency)

- Lack of integrity of the upper GI tract: malabsorption syndrome or major surgery of
the stomach or the small intestine

- Severe renal impairment (creatinine clearance < 30 ml/min)

- Severe psychiatric disorder (other than controlled depressive syndrome)

- Patient participating in another experiment

- Pregnant women