Cetuximab Monotherapy Maintenance Treatment in mCRC

Inclusion Criteria: * Histological proof of colorectal cancer (in case of a single metastasis, histological or cytological proof of this lesion should be obtained); * Distant metastases (patients with only local recurrence are not eligible); * Unidimensionally measurable disease (\> 1 cm on spiral CT scan or \> 2 cm on chest X-ray; liver ultrasound is not allowed). Serum CEA may not be used as a parameter for disease evaluation; * In case of previous radiotherapy, at least one measurable lesion should be located outside the irradiated field; * Ongoing or planned first line treatment with 6 cycles of mFOLFOX6/FOLFIRI plus Cetuximab. At randomisation: * WHO performance status 0-1 (Karnofsky PS \> 70%); * Laboratory values obtained ≤ 2 weeks prior to randomisation: * adequate bone marrow function (Hb \> 6.0 mmol/L, absolute neutrophil count \> 1.5 x 109/L, platelets \> 100 x 109/L), * renal function (serum creatinine ≤ 1.5x ULN and creatinine clearance, Cockroft formula, \> 30 ml/min), * liver function (serum bilirubin ≤ 2 x ULN, serum transaminases ≤ 3 x ULN without presence of liver metastases or ≤ 5x ULN with presence of liver metastases); * Negative pregnancy test in women with childbearing potential; * Expected adequacy of follow-up; * Institutional Review Board approval; * Written informed consent Exclusion criteria; * History or clinical signs/symptoms of CNS metastases; * History of a second malignancy ≤ 5 years with the exception of adequately treated carcinoma of cervix or basal/squamous cell carcinoma of skin. Exclusion Criteria: * Prior adjuvant treatment for stage II/III colorectal cancer ending within 6 months before the start of induction treatment; * Any prior adjuvant treatment after resection of distant metastases; * Previous systemic treatment for advanced disease.