Inclusion Criteria:

- Histologically confirmed locally advanced or metastatic colorectal cancer

- Measurable or evaluable disease

- ECOG performance status ≤ 2

- Age 18 - 72 years

- Adequate liver (Bilirubin ≤ 1.5 UNL, SGOT/SGPT ≤ 4 UNL, ALP ≤ 2.5 UNL), renal
(Creatinine ≤ 1.5 UNL) and bone marrow (ANC ≥ 1,500/mm3, PLT ≥ 100,000/mm3) function

- Patients with history of hemoptysis or with increased risk of thromboembolic events
should be observed carefully due to administration of Avastin

- Patients must be able to understand the nature of this study

- Written informed consent

Exclusion Criteria:

- Previous 1st line chemotherapy

- Adjuvant chemotherapy with Irinotecan regimen with relapse < 6 months after the
completion

- Active infection

- History of serious cardiac disease (unstable angina, congestive heart failure,
myocardial infarction within the previous 6 months, ventricular arrhythmias)

- Previous radiotherapy within the last 4 weeks or > 25% of bone marrow

- Patients with unstable CNS metastases

- Patients with chronic diarrhea (at least for 3 months) or partial bowel obstruction

- Second primary malignancy, except for non-melanoma skin cancer and in situ cervical
cancer

- Psychiatric illness or social situation that would preclude study compliance

- Pregnant or lactating women

- Patients > 65 years with history of arterial thromboembolic, myocardial infarction,
unstable angina and pulmonary embolism