Phase II Trial of FOLFOXIGIL Versus FOLFOXIRI as First-line Therapy in Patients With mCRC

Inclusion Criteria: * histological or cytological documentation of adenocarcinoma of the colon or rectum. * unresectable metastatic disease * age 18 to 75 years * Eastern Cooperative Oncology Group (ECOG) performance status of 2 or lower if age 70 years or younger or ECOG performance status of 0 if age 71 to 75 years * at least one measurable lesion according to Response Evaluation Criteria in Solid Tumors (RECIST) criteria measured within 4 weeks prior to registration. * no previous chemotherapy or target therapy for metastatic disease (adjuvant chemotherapy for non-metastatic disease is allowed if terminated more than 6 months ago). * adequate bone marrow, hepatic and renal function as assessed by the following laboratory requirements conducted within 7 days of starting study treatment: * Leukocytes ≥ 3.0 x109/ L, absolute neutrophil count (ANC) ≥ 1.5 x109/ L, platelet count ≥ 100 x109/ L, hemoglobin (Hb) ≥9g/ dL. * Total bilirubin ≤ 1.5 x the upper limit of normal (ULN). * Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 5 x ULN. * Alkaline phosphatase limit ≤ 5x ULN. * Amylase and lipase ≤ 1.5 x the ULN. * Serum creatinine ≤ 1.5 x the ULN. * Calculated creatinine clearance or 24 hour creatinine clearance ≥ 50 mL/ min. Exclusion Criteria: * previous palliative chemotherapy for metastatic disease * previous chemotherapy including irinotecan or oxaliplatin * symptomatic cardiac disease, myocardial infarction in the last 24 months or uncontrolled arrhythmia * active infections * pregnancy or lactation at the time of study entry. * inflammatory bowel disease * major autoimmune diseases * acquired immunosuppression (AIDS or major immunosuppressive agents)