This randomized phase III trial studies oxaliplatin, leucovorin, fluorouracil, and bevacizumab to see how well they work compared to oxaliplatin, leucovorin, and fluorouracil in treating patients who have undergone surgery for stage II colon cancer. Drugs used in chemotherapy, such as oxaliplatin, leucovorin, and fluorouracil, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Monoclonal antibodies, such as bevacizumab, may interfere with the ability of tumor cells to grow and spread. It is not yet known whether giving combination chemotherapy together with bevacizumab is more effective than combination chemotherapy alone in treating colon cancer.

PRIMARY OBJECTIVES: I. To demonstrate an improvement in 3-year disease-free survival for high-risk stage II colon cancer patients randomly assigned to 5-FU (fluorouracil), leucovorin, oxaliplatin versus 5-FU, leucovorin, oxaliplatin and bevacizumab. SECONDARY OBJECTIVES: I. To compare overall survival between the regimens. II. To further define the toxicity profiles of the regimens. III. To prospectively determine the impact of tumor biological characteristics on the survival of patients with stage II colon cancer. IV. To assess the association between oxaliplatin exposure, allelic variants in candidate genes, and neurotoxicity. (Pharmacogenetic ancillary objective) OUTLINE: Patients with high-risk disease are randomized to 1 of 2 treatment arms (Arms A and B). Patients with low-risk disease are assigned to Arm C. ARM A: Patients receive oxaliplatin intravenously (IV) over 2 hours and leucovorin IV over 2 hours on day 1. Patients also receive fluorouracil IV continuously over 46 hours beginning on day 1. Treatment repeats every 2 weeks for 12 courses in the absence of disease progression or unacceptable toxicity. ARM B: Patients receive oxaliplatin, leucovorin, and fluorouracil as in Arm A and bevacizumab IV over 30-90 minutes on day 1. Treatment repeats every 2 weeks for 12 courses in the absence of disease progression or unacceptable toxicity. Patients then receive bevacizumab alone for 12 additional courses in the absence of disease progression or unacceptable toxicity. ARM C: Patients undergo observation. After completion of study treatment, patients are followed up every 3 months for 2 years, every 6 months for 3 years, and then every 12 months for 10 years.