Maintenance Treatment Versus Observation After Induction in Advanced Colorectal Carcinoma

Before the start of induction therapy: 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 Xeloda, Eloxatin, and Avastin. 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 At randomisation: Inclusion criteria: * WHO performance status 0-1 (Karnofsky PS \> 70%); * Disease evaluation with proven SD, PR or CR according to RECIST after 6 cycles of MTD chemotherapy performed in week 3-4 of the 6th cycle induction therapy, and randomisation performed in week 3-5 of the 6th cycle (see time table); * 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); * Life expectancy \> 12 weeks; * Age \>= 18 yrs; * 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; * Previous intolerance of XelodaR, EloxatinR, and/or AvastinR for which any of these drugs have been permanently discontinued; patients with previous dose reductions or delays are eligible; patients with grade 2 neurotoxicity after the 6th cycle are eligible, and retreatment with EloxatinR after PFS1 should depend on the grade of neurotoxicity at that moment; * Known dihydropyrimidine dehydrogenase (DPD) deficiency; * (Planned) radical resection of all metastatic disease; * Uncontrolled hypertension, i.e. consistently \> 150/100 mmHg; * Use of more than 3 antihypertensive drugs; * Significant cardiovascular disease \< 1 yr before randomisation (symptomatic congestive heart failure, myocardial ischemia or infarction, unstable angina pectoris, serious uncontrolled cardiac arrhythmia, arterial thrombosis, cerebrovascular event, pulmonary embolism); * Any of these significant cardiovascular events during previous fluoropyrimidine therapy; * Chronic active infection; * Any other concurrent severe or uncontrolled disease preventing the safe administration of study drugs; * Any impairment of gastrointestinal function or -disease that may significantly impair the absorption of oral drugs (i.e. uncontrolled nausea, vomiting, diarrhoea (defined as \>CTC grade 2), malabsorption syndrome, bowel obstruction, or inability to swallow tablets); * Concomitant treatments: concomitant (or within 4 weeks before randomisation) administration of any other experimental drug under investigation; concurrent treatment with any other anti-cancer therapy; full-dose anticoagulation (is allowed if started during induction therapy); * Continuous use of immunosuppressive agents (except the use of corticosteroids as anti-emetic prophylaxis/treatment).