Phase II Study to Evaluate Safety and Efficacy of Cetuximab in Combination With XELOX for 12 Weeks Followed by Maintenance Treatment With Cetuximab Plus Capecitabine as First-line Treatment in Elderly Patients With Metastatic Colorectal Cancer.

Inclusion Criteria:

* Signed written informed consent before any study related activities are carried out
* Men and women \>= 70 years.
* Histologically confirmed diagnosis of CRC.
* Non-resectable and/or non-operable metastatic colorectal carcinoma.
* Presence of at least one lesion by two-dimensional measurement; index lesions should not be in a region with previous irradiation.
* Availability of tumor tissue for immunohistochemical analysis
* Karnofsky functional status \>= 80% at the time of enrollment in the study.
* Life expectancy greater than 3 months.
* Patients will not have received chemotherapy for advanced or metastatic disease. Patients with the following characteristics will be included: 1. Recurrence after neoadjuvant and/or adjuvant treatment with 5-fluorouracil/folinic acid or capecitabine +/- radiotherapy with disease-free interval \> 12 months following conclusion of treatment. 2. Recurrence after surgical and/or radiotherapy treatment without adjuvant systemic treatment. 3. De novo diagnosis of disease.
* Proper hematological, renal and hepatic function,

Exclusion Criteria:

* Documented or suspected cerebral and/or leptomeningeal metastases.
* Surgery (excluding biopsy for diagnosis) and/or radiotherapy during the 4 weeks prior to inclusion in the study.
* Chronic, concomitant systemic immunotherapy, chemotherapy, or hormonal treatment for cancer.
* Prior administration of monoclonal antibodies, EGFR signal transduction inhibitors or EGFR-targeted treatment.
* Participation in another clinical trial with medication in the past 30 days
* Prior participation in a study in which treatment with cetuximab may be assigned (whether or not treatment with cetuximab is received).
* Prior malignant tumor in the past 5 years, except for history of adequately treated basal cell skin cancer or pre-invasive cervical cancer .
* Lack of physical integrity of the upper gastrointestinal tract or malabsorption syndrome or history of inflammatory intestinal disease, acute or subacute intestinal occlusion or other disease which could alter drug absorption.
* Evidence of grade 3 or 4 allergic reaction to any treatment components or other fluoropyrimidines.
* Clinically relevant peripheral neuropathy.
* Clinically significant coronary artery disease or history of myocardial infarction in the last 12 months or high risk of decompensation of heart failure or arrhythmia.
* Serious active infections (requiring intravenous antibiotics), including active tuberculosis and diagnosed HIV.
* Known abuse of alcohol/drugs.
* Legal incapacity or limited legal capacity.
* Any medical or psychological disorder which, in the opinion of the investigator, does not allow the patient to conclude the study or sign the informed consent.
* Patients catalogued as delicate or "frail" for compliance with any of the following criteria

  * Dependence in one or more activities of daily life according to the Katz Activity of Daily Living (ADL) scale.
  * 3 or more comorbid entities based on evaluation of the presence of the following processes: congestive heart failure; valvular heart disease; coronary artery disease; obstructive or restrictive chronic pulmonary disease; cerebrovascular disease; peripheral neuropathies; chronic renal failure; hypertension; diabetes; concomitant neoplasms; collagen vascular diseases; and incapacitating arthritis.
  * Presence of geriatric syndromes: moderate-severe dementia; delirium in situation of stress (urinary or respiratory infection, angina or drugs); moderate-severe depression that interferes with usual activity of patient; frequent falls (3 or more per month); lack of care (Who could help him or her in the event of an emergency?); urinary incontinence in the absence of stress, infection, diuretics or prostatic hyperplasia; fecal incontinence in the absence of diarrhea or laxatives; osteoporotic fractures of long bones or vertebral crush.