Combination Chemotherapy Plus Bevacizumab With or Without Oxaliplatin in Treating Older Patients With Metastatic Colorectal Cancer

Inclusion Criteria * Patients must have metastatic colorectal cancer that has been histologically or cytologically confirmed; Note: histologic confirmation can be obtained from the primary tumor with appropriate imaging studies confirming metastatic spread * Eastern Cooperative Oncology Group performance status (ECOG PS) 0, 1, or 2 * Absolute neutrophil count (ANC) \>= 1,500/mm\^3 * Peripheral platelet count (PLT) \>= 100,000/mm\^3 * Hemoglobin (HgB) \> 9.0 g/dL * Total bilirubin =\< 1.5 x upper limit of normal (ULN) * Aspartate transaminase (AST) =\< 2.5 x ULN (=\< 5 x ULN for patients with liver involvement) * Alkaline phosphatase =\< 3 x ULN (=\< 5 x ULN for patients with liver involvement) * Creatinine =\< 1.5 x ULN * International normalized ratio (INR) \< 1.5 x ULN unless patients are receiving anti-coagulation therapy; patients receiving prophylactic anti-coagulation therapy with an agent such as warfarin or heparin are allowed to participate if INR =\< 3.0 * Urine protein creatinine (UPC) ratio \< 1 or urine dipstick \< 2+ \* NOTE: Urine protein must be screened by urine analysis for urine protein creatinine (UPC) ratio or by dip stick; for UPC ratio \>= 1.0 or urine dipstick \>= 2+, 24-hour urine protein must be obtained and the level should be \< 1000 mg * Life expectancy \>= 3 months * Ability to complete questionnaire(s) by themselves or with assistance * Provide informed written consent * Willing to provide mandatory blood samples for correlative research pur…