Inclusion Criteria:

- Histologically confirmed colorectal adenocarcinoma, initially diagnosed or recurred

- Unresectable, locally advanced or metastatic

- At least one uni-dimensional measurable lesion by RECIST criteria

- Age 18 to 75 years old

- Estimated life expectancy ≥3 months

- ECOG performance status ≤2

- Adequate bone marrow function (WBCs ≥ 4,000/µL or absolute neutrophil count ≥
1,500/µL, platelets ≥ 100,000/µL)

- Adequate kidney function (creatinine < 1.5 mg/dL)

- Adequate liver function (bilirubin < 2.0 mg/dL, transaminase levels <2.5 times the
upper normal limit)

- Written informed consent

Exclusion Criteria:

- Other tumor type than adenocarcinoma

- Previous history of chemotherapy (exception : neoadjuvant or adjuvant chemotherapy
without oxaliplatin)

- Presence of CNS metastasis, psychosis, or seizure

- Obvious bowel obstruction

- Evidence of serious gastrointestinal bleeding

- Past or concurrent history of neoplasm other than colorectal adenocarcinoma, except
for curatively treated non-melanoma skin cancer or in situ carcinoma of the cervix
uteri

- Pregnant or lactating women, women of childbearing potential not employing adequate
contraception

- Other serious illness or medical conditions