1.1 To collect pathological tumor specimens of patients with metastatic colorectal cancer in a prospective fashion for correlative studies of response to an oxaliplatin based chemotherapy regimen.

1.2 To determine a gene expression profile that predicts response to an oxaliplatin based chemotherapy regimen in this cohort of patients.

This is a single-arm, non-randomized trial of oxaliplatin and capecitabine. Patients that are placed on other studies that utilize the same chemotherapy regimen can enter this study. Those patients will be treated according to the clinical study on which they have been entered. For patients not on another clinical trial, the treatment outlined below should be followed.

Inclusion Criteria:

• All patients, >18 years of age, with metastatic/recurrent colorectal cancer are eligible.
• Patients must have a life expectancy of at least 12 weeks.
• Patients must have a Zubrod performance status of 0-2.
• Patients must sign an informed consent.
• Patients should have adequate bone marrow function defined by an absolute peripheral granulocyte count of > 1,500 or cells/mm3 and platelet count > 100,000/mm3 and absence of a regular red blood cell transfusion requirement.
• Patients should have adequate hepatic function with a total bilirubin < 2 mg/dl and SGOT or SGPT < two times the upper limit of normal, and adequate renal function as defined by a serum creatinine < 1.5 x upper limit of normal.
• The patient must agree to a biopsy of a sample of tumor for correlative studies.
• The patient is an appropriate candidate for oxaliplatin/capecitabine based chemotherapy.
• The patient must have measurable disease.

Exclusion Criteria:

• Patients with symptomatic brain metastases are excluded from this study.
• Pregnant women or nursing mothers are not eligible for this trial. Patients of child bearing potential must use adequate contraception.
• Patients may receive no other concurrent chemotherapy or radiation therapy during this trial.
• Patients with severe medical problems such as uncontrolled diabetes mellitus or cardiovascular disease or active infections are not eligible for this trial.
• Patients may not have received oxaliplatin previously.
• Patients with a prior unanticipated severe reaction to fluoropyrimidine therapy, or known dihydropyrimidine dehydrogenase (DPD) deficiency, or known hypersensitivity to platinum compounds or any of the components of the study medications.