Cetuximab & Celecoxib for Metastatic Colorectal Cancer or Colorectal Cancer That Cannot Be Removed by Surgery

RATIONALE: Monoclonal antibodies, such as cetuximab, can block tumor growth in different ways. Some block the ability of tumor cells to grow and spread. Others find tumor cells and help kill them or carry tumor-killing substances to them. Cetuximab may also stop the growth of colorectal cancer by blocking blood flow to the tumor. Celecoxib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Giving cetuximab together with celecoxib may kill more tumor cells.
PURPOSE: This phase II trial is studying how well giving cetuximab together with celecoxib works in treating patients with metastatic colorectal cancer or colorectal cancer that cannot be removed by surgery.