Study of S-1 Plus LV for Untreated Metastatic Colorectal Cancer

Inclusion Criteria: * Histologically proved adenocarcinoma * Unresectable and recurrent colorectal cancer * Age20 ≤ at enrollment * Performance status 0 or 1 (ECOG) * No prior treatment (ex. radiation therapy, chemotherapy, hormonal therapy) to advanced disease. Patients who received adjuvant chemotherapy more than 180 days before enrollment can be allowed but those who received S-1 containing treatment shall be excluded * Adequate hematologic, hepatic and renal functions * At least one measurable lesion by RECIST criteria Exclusion Criteria: * Serious drug hypersensitivity * Pregnant or nursing * Bleeding from gastrointestinal tract * Diarrhea * Simultaneously active double cancer * Serious illness or medical condition * Brain metastasis