G-CSF in Preventing Neutropenia During First-Line Treatment With Chemotherapy and Bevacizumab in Patients With Metastatic Colorectal Cancer

DISEASE CHARACTERISTICS: Inclusion criteria: * Histologically confirmed adenocarcinoma of the colon or rectum * Metastatic disease * Not surgically curable * Homozygous for allele UGT1A1\*28, the promoter of the gene coding for UGT1A1 (genotype 7/7) * Measurable and/or evaluable disease Exclusion criteria: * Original tumor not removed * CNS metastases * Secondary localized cerebral tumors PATIENT CHARACTERISTICS: Inclusion criteria: * WHO performance status 0-2 * ANC ≥ 1,500/mm\^3 * Platelet count ≥ 100,000/mm\^3 * Hemoglobin ≥ 9 g/dL * Creatinine \> 1.5 mg/dL * Total bilirubin ≤ 1.5 times normal * Alkaline phosphatase ≤ 2.5 times normal (5 times normal if liver involvement) * Not pregnant or nursing * Negative pregnancy test * Fertile patients of must use effective contraception Exclusion criteria: * Progressive gastroduodenal ulcer, prior hemorrhagic ulcer, or perforation in the past 6 months * Enteropathy or chronic diarrhea * Chronic inflammatory intestinal disease * Intestinal obstruction * Active cardiac disease including any of the following: * Uncontrolled hypertension * Myocardial infarction in the past 12 months * Serious angina * NYHA class II-IV congestive heart failure * Severe arrhythmia (even if treated) * Peripheral vascular disease ≥ grade 2 * Unhealed wound, ulcer, or severe bone fracture * Bleeding disorder or coagulopathy * Severe uncontrolled infection or medical condition * Proteinuria \> 500 mg/24 hours * Other malignancy within the past 5 years except basal cell skin cancer or curatively treated carcinoma in situ of the cervix * Known dihydropyrimidine dehydrogenase deficiency * Severe traumatic injury within the past 4 weeks PRIOR CONCURRENT THERAPY: Inclusion criteria: * At least 2 weeks since prior radiotherapy Exclusion criteria: * Prior chemotherapy for metastatic disease except adjuvant chemotherapy completed \> 6 months ago * Prior irinotecan hydrochloride or bevacizumab * Major surgery or biopsy within the past 4 weeks * Major surgery planned * Puncture in the past week * Chronic aspirin (\> 325 mg/day) or NSAIDs * Concurrent antifungal azoles (e.g., ketoconazole, fluconazole, itraconazole) * Concurrent phenytoin (as in yellow fever vaccine) * Concurrent Hypericum perforatum (St. John's wort) * Oral or parenteral coagulant in the past 10 days and during study therapy * Warfarin allowed provided INR \< 1.5